Phospholipid analogs as diapeutic* agents and methods thereof

ABSTRACT

The present invention provides methods and uses of phospholipid ether analogs as diagnostic and therapeutic agents for numerous cancers.

RELATED APPLICATION

The present application seeks priority from U.S. Provisional Application60/521,166, filed on Mar. 2, 2004, which is incorporated herein byreference for all purposes.

BACKGROUND OF INVENTION

The invention generally relates to diagnostic imaging of tumors andspecifically relates to diagnostic imaging of tumors using phospholipidanalogs.

The early detection of cancer has been one of the primary goals ofmodern imaging technology, since the identification of a suspected tumorin a localized stage significantly improves the chances for successfultreatment and elimination of the cancerous tissue. A large number ofimaging strategies have therefore been designed, using a variety oftechniques and modalities, to aid the physician in making an accuratediagnosis as early as possible.

Unfortunately, conventional imaging techniques such as computerizedtomography (CT) and MRI (magnetic resonance imaging) are limited intheir ability to afford a conclusive diagnosis of a suspected lesion,since they are only capable of observing differences in the density ormorphology of tissues. A more invasive and costly biopsy procedure isoften necessary to provide a definitive diagnosis. In contrast, nuclearmedicine techniques such as positron emission tomography (PET) andsingle photon emission tomography (SPECT) can provide functional orbiochemical information about a particular organ or area of interest.However, the success of these nuclear imaging techniques depends inlarge part on the selective uptake and detection of appropriateradiopharmaceuticals. Selective uptake, in turn, depends upon thedevelopment of radiopharmaceuticals with a high degree of specificityfor the target tissue. Unfortunately, the tumor-localizing agentsdeveloped thus far for oncological applications have had only limitedapplication.

For example, one of these prior art compounds, ⁶⁷Ga gallium citrate, wasoriginally identified for its ability to accumulate in tumor tissue.Unfortunately, ⁶⁷Ga gallium citrate is taken up by a variety of othernon-cancerous lesions as well, including inflammatory lesions, andunacceptable amounts of radioactivity can also accumulate in liver andspleen tissue. The rapid buildup of a radiopharmaceutical in theseorgans can seriously interfere with the imaging of nearby lesions andalso negatively impacts the dosage that can safely be given to apatient.

An alternative approach has been to develop radiolabeled monoclonalantibodies (Mabs) directed to tumor-specific antigens. However, thesemonoclonal antibodies are specific only to the particular tumor tissuefor which they have been produced, and therefore will not localizegenerally in neoplastic tissue. Moreover, the use of Mabs for diagnosticimaging has lead to additional problems, including varying degrees ofantigen expression, low tumor uptake, non-specific binding and adverseimmunogenic reactions.

In an attempt to address these problems, the present inventors haverecently identified and developed a series of novel compoundsdemonstrating useful tumor specificity. See, e.g., U.S. Pat. Nos.4,925,649; 4,965,391; 5,087,721; 5,347,030 and 6,417,384; all of whichare herein incorporated by reference. It is believed that theseradioiodinated phospholipid ether analogs take advantage of a uniquebiochemical characteristic of malignant tumor cells; i.e. the largeconcentration of naturally-occurring ether lipids in the tumor cellmembranes relative to corresponding normal tissues. Although the precisemechanism of action is not fully understood, the prevailing hypothesisis that the phospholipid ether analogs become entrapped in tumormembranes. Accordingly, these compounds localize in tumor tissue andremain in place for diagnostic and/or therapeutic applications.

The selective retention of the radiolabeled phospholipid ether analogsdescribed in the above patents has been demonstrated in a variety ofrodent and animal tumor xenografts and not in spontaneous tumor modelswhich are thought to more closely mimic the human disease.Unfortunately, the data obtained from these studies has alsodemonstrated a relatively rapid clearance of the radiopharmaceuticalcompound from the blood, and an undesirable accumulation by non-targettissues. As noted above, non-target tissue uptake can decrease theefficacy of radiodiagnostic imaging by creating high backgroundactivity, or by causing excessive exposure of radiosensitive tissues tothe injected radioactivity.

Accordingly, there remains a significant need in the art forradiopharmaceuticals which exhibit a rapid clearance from non-targettissues as well as an extended half-life in the plasma, while stillretaining its specificity and avidity for neoplastic tissue. Such anagent should not only assist in the non-invasive imaging of primarytumors and metastases, but should also serve as a carrier for acytotoxic agent for site-specific eradication of malignant tumor tissue,especially as it relates to most frequently diagnosed forms of cancers.It is further desirable that radiopharmaceuticals are selective formalignant tumors and not precancerous tissues including adenomas andhyperplasia.

Approximately 147,000 new cases of colorectal cancer are diagnosed eachyear in the United States. Thus colorectal cancer is the fourth mostcommon cancer, accounting for 60,000 deaths per year.¹ Treatment dependsprimarily on the cancer stage, but may include surgery, radiation,chemotherapy, and/or radiofrequency or cryo ablation. In routinefollow-ups for colorectal cancer patients, however, determination ofcarcinoembryonic antigen (CEA), a colorectal tumor marker, and repeatcolonoscopies⁵ fail to detect recurrent disease in over 50% ofpatients.⁶ Therefore, there is a need for development of additionalmethods for detection of recurrent disease. Further, during treatmentand diagnosis using CT scanning and RF ablation, functional informationfrom CT scans is difficult to obtain. With contrast-enhanced helical CT,the tumor vascularity may be assessed to some degree, but there is noway of accurately determining if viable tumor cells remain within the RFlesion. In addition, the thermal lesions created by RF normally have arim of inflammation surrounding them on post procedure CT scans for upto 6 months post-procedure. PET scanning has been used to followpost-ablation patients, but the rim of inflammation surrounding RFthermal lesions normally displays increased uptake, even in the absenceof viable tumor. This decreases the sensitivity and specificity forearly detection of recurrent tumor. Accordingly, agents like NM404 thatare selective for and retained indefinitely by malignant tumor cells arepreferable, unlike FDG which is not selective for tumor cells and goesto infectious sites and hyperplasias (Barret's Esophagus). Moreover,compounds like NM404 containing ¹²⁴I, which has a 4 day physicalhalf-life and can be shipped anywhere in the world, are preferable ascompared to FDG which has a 110 minute half-life and therefore may onlybe have limited distribution within 200 miles of the production site.Further compounds like NM404 that undergo prolonged retention (notmetabolized) are preferable since it is more likely that they may havesignificant therapeutic potential when mated with an appropriateradioisotope like ¹³¹I. Also, compounds like NM404, which can be labeledwith a variety of iodine isotopes and have expanded versatility(diagnosis and therapy as well as a tool for experimental animalstudies) are preferable as compared to FDG, which is limited to ¹⁸F forPET scanning or potentially ¹⁹F (stable) for magnetic resonance imagingalbeit at very low sensitivity levels. Regardless of its tumor targetingability, FDG due to its rapid metabolism in tumor cells, does not havepotential for therapy. Therefore, other compounds are needed toinvestigate post RF local recurrences. Likewise, if the tumor becomesmetastatic, either by progression or recurrence of the local tumor, ahybrid imaging modality (PET and CT combination), replacingpost-procedure separate CT and PET scanning is highly desirable.

Moreover, even where chemotherapy is the mode of treatment, improvedmonitoring of the response to chemotherapy is essential. Therefore,development of an early marker to study response to chemotherapy toallow physicians to quickly discontinue use of ineffectivechemotherapeutic regimens without exposing patients to the toxicity ofprolonged treatments is desirable. Where External Beam Radiation Therapyis an alternate treatment for patients with tumors of similar histology,tumors may have dramatically different responses to curative-intentexternal radiation therapy (XRT). Some patients with rectal cancertreated with pre-operative radiation will have a complete response,while others with similar histology (at the light microscopy level) willhave a poor response to treatment and disease will recur. Response toradiation is a predictive factor for ultimate tumor control and survivalfor many cancers, including many gastrointestinal cancers, lung cancer,head and neck cancer, and gynecologic cancers. Most responsecharacterization methods, while very predictive of response, areperformed after completion of treatment. While some intra-treatmentclinical assessments are useful in adjusting treatment,¹⁴ in most casesthere is no accurate method of predicting tumor response during actualtreatment. Such a test, especially one applicable to a broad range oftumor sites and histologies, would obviously be very useful anddesirable. Other treatment and diagnostic methods include molecularassays that have been proposed to predict response to therapy, andrecent efforts include use of DNA microarrays to identify geneticchanges that correlate with response or lack of response to treatment.These are investigational and none are in routine clinical use.

Yet other methods of diagnosis and treatment include use of imagingmodalities to predict response during XRT treatment. Intra-treatment PETscans using FDG are under active investigation, wherein the isotopeuptake in the primary tumor midway through radiation therapy is comparedto the pre-treatment uptake. Several retrospective studies suggestpatients with continued strong uptake during treatment have poorer tumorcontrol outcomes than patients whose tumors are less FDG-avid duringtreatment.¹⁵ However, more effect screening, diagnostic and treatmentmethods for various cancers are extremely desirable.

Other well observed tumors include malignant gliomas that are the mostcommon type of primary brain tumors. Despite aggressive treatment withsurgery, radiation, and chemotherapy, most patients harboring thesetumors have less than a two-year survival after diagnosis. Recentadvances in neuroradiology and magnetic resonance imaging (MRI) havemade a significant impact in early diagnosis and treatment of thesetumors. Most malignant gliomas, however, have an infiltrative component,which is poorly differentiated from edematous brain tissue by presentimaging techniques. It is often this component of the tumor that is mostdifficult to treat and responsible for local recurrence. Undoubtedly,better visualization of invasive glioma cells is desirable forsignificant therapeutic treatment.

Likewise, pancreatic cancer is a highly lethal disease with the poorestlikelihood of survival among all of the major malignancies. It is thefifth leading cause of cancer death in the United States and of all thenewly diagnosed cancers in the United States, 2% per year are due topancreatic cancer. However, it is one of the most highly lethal diseaseswhich accounts for 5% of all cancer deaths. Miller B A, et al. NIH Pub.No. 96-4104. Bethesda, Md. 1996. This is demonstrated by the fact thatthere are no five-year survivors in patients with unresectable disease.In addition, although surgical resection offers the only hope for cure,the five-year survival after resection is only 20%. Geer R J, Brennan MF. Am J Surg 1993; 165:68-72; Yeo C J, Cameron J L, et al., Ann Surg1997. Although PET scanning with 18-FDG has shown promise in imaging avariety of other primary cancers, it appears to have only limitedability to improve upon the imaging capability of CT scan for patientswith pancreatic cancer, particularly in assessing for metastaticdisease. Kasperk R K, Riesener K P, et al., World J Surg 2001;25:1134-1139; Sendler A, Avril N, et al., World J Surg 2000;24:1121-1129. Thus, there remains a need for a method of accuratelyimaging patients with occult metastatic pancreatic cancer.

Hepatocellular cancer is the most common solid organ malignancyworldwide, due to its common etiology of chronic liver damage fromhepatitis or alcoholism. Incidence rates vary markedly, from 2.1 per100,000 in North America to 80 per 100,000 in high-incidence regions ofChina. The risk of developing HCC in patients with cirrhosis is 1-6% peryear. Although resection is the only curative option, only 10-30% ofpatients are candidates for surgery at the time of presentation, due toeither poor hepatic reserve or the presence of unresectable ormetastatic disease. Attesting to the aggressive nature of this disease,the five-year survival is only 15-35% after curative resection. TreiberG. Digestive Diseases (2001) 19:311-323.

Breast cancer is a major health concern for women in the United Statestoday. It was anticipated that nearly 216,000 women in the US alonewould be diagnosed with breast cancer in 2004 and of these 40,000 wereexpected to die. Accurate assessment of local, regional and distantmetastatic spread is critical for optimal disease treatment andmanagement. The development of a non-invasive imaging modality thatwould allow detection and or characterization of local or distant breastcancer metastases including lymph node involvement would represent asignificant advancement in the management of this disease. Althoughmammography is the current screening method of choice for initialdetection of breast cancer, histologic confirmation and regional spreadto neighboring lymph nodes are typically evaluated via biopsy. Moresophisticated imaging methods including scintigraphic scanning with^(99m)Tc-Sestamibi and ¹⁸F-FDG PET scanning have now been extensivelyexamined, but have not impacted treatment planning significantly duemainly to unpredictable specificity. Wahl R L. Quart J of Nucl Med(1998) 42:1-7. The role of PET scanning has indicated efficacy, however,in monitoring tumor response to chemotherapy. Smith I C, Welch A E, etal., J of Clin Oncol (2000) 18:1676-1688; Schelling M, Avril N, et al.,J of Clin Oncol (2000) 18:1689-1695. Radiation therapy has awell-established role in the treatment of breast cancer due mainly tothe sensitivity of many solid epithelial tumors, including infiltratingductal carcinoma, to ionizing radiation. DeVita V, Hellman S, RosenbergS. Cancer: Principles and Practice of Oncology, 6th edition.Philadelphia (Pa.): Lippincott, Williams and Wilkins, 2002, pp.1667-1680. The most common indication for radiation in breast cancer isas adjuvant treatment following lumpectomy or mastectomy. In thiscontext, radiation therapy has been shown to dramatically decrease theincidence of local and regional recurrence by sterilizing microscopicdeposits in these tissues. Chemotherapy is offered when the patient hasmetastatic disease or is deemed to have an increased risk for occultmetastases. In this latter indication, that of adjuvant chemotherapyadministration, studies confirm improved survival in patients receivingadjuvant chemotherapy or hormonal therapy. Radiation is also used in thepalliative setting with good effect in reducing the pain and volumeeffects of metastases in solid organs and bone. Many patients relapseafter definitive therapy for reasons that are multifactorial. Acquiredresistance to radiation and chemotherapy undoubtedly contributes torecurrence after primary therapy. Additionally, the use of radiation isassociated with specific toxicities which are generally late-occurringand dose-limiting. Fibrosis, nerve damage, and soft tissue necrosis canbe severe if excessive doses of radiation are used. Arm lymphedema isthe most common and dreaded toxicity for breast cancer patients, andresults most commonly from the combination of axillary dissection (donefor diagnostic purposes) and adjuvant radiation to the axilla.

In contrast to new anticancer drugs that are largely targeted toreceptors or molecules specific to each particular tumor type, newcompounds that rely on a common mechanism applicable to a variety ofdifferent tumor types are extremely desirable.

Hence, there remains a dire clinical need for noninvasive breast cancerimaging techniques that afford both high sensitivity and specificity.Moreover, the potential to deliver a therapeutic dose of iodine-131simultaneously to both primary and metastatic tumors is a significantadded benefit.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer deathin the United States today. Surgical resection in appropriately selectedpatients offers the best chance for long-term survival and may becurative. Accurate pre-operative assessment of local, regional anddistant metastatic spread is thus critical for optimal management.Evaluation of the mediastinal lymph node status is essential becausenodal metastasis, which occurs in nearly half of all patients withNSCLC, is probably the most frequent barrier to cure. Accurate stagingmay also spare patients the morbidity of unnecessary, non-curativesurgical procedures.

Imaging with FDG-PET scanning is quickly becoming the gold standard forimaging NSCLC, due to improved sensitivity rates, particularly whencompared with CT imaging. However, this is an expensive imaging testwhich is not available in most community practices. Hence, there remainsa need for an imaging technique which is sensitive, specific, and usesresources which are readily available to most patients.

Positron-emission tomography (PET) scanning with ¹⁸F-FDG has generatedconsiderable interest as an imaging technique. A recent studyprospectively compared the ability of a standard approach to staging forNSCLC (CT, ultrasound, bone scanning, etc) and PET scanning to detectmetastases in mediastinal lymph nodes and distant sites. Pieterman R M,vanPutten J W G, Meuzzelaar J J, Mooyaart E L, Valburg W, Koeter G H,Fidler V, Prium J, Groen H J M. Preoperative Staging of Non-Small CellLung cancer with Positron-Emission Tomography. New Eng J Med343:254-261, 2000. Mediastinal involvement was confirmedhistopathologically, and distant metastases were confirmed by otherimaging tests. The sensitivity and specificity of PET for detectingmediastinal metastases were 91% and 86%, respectively; for detectingdistant metastases, 82% and 93%, respectively. This compares tosensitivity and specificity for CT scanning of mediastinal involvement75% and 66%, respectively. Another study compared imaging with FDG-PET,CT, and histology results. Overall sensitivity, specificity, andaccuracy of PET for staging mediastinal nodes (n=168 in 54 patients) was96%, 93% and 94%, as compared to 68%, 65%, and 6% with CT. Gupta N C,Graeber G M, Bishop H A. Comparative efficacy of positron emissiontomography with fluorodeoxyglucose in evaluate of small (<1 cm),intermediate (1 to 3 cm), and large (>3 cm) lymph node lesions. Chest117(3):773-778, 2000. Limitations of PET scanning, however, include thecost, limited availability, inability to detect lesions under 1 cm, andlack of specificity, particularly in patients with inflammatory orgranulomatous disease. Stokkel M P, Bakker P F, Heine R, Schlosser N J,Lammers J W, Van Rijk P P. Staging of lymph nodes with FDG dual headedPET in patients with non-small cell lung cancer. Nucl Med Communications20(11):1001-1007, 1999; Kapuco L O, Meltzer C C, Townsend D W, Keenan RJ, Luketich J D. Fluorine-18-fluoro-deoxyglucose uptake in pneumonia. JNucl Med 39(7):1267-1269, 1998.

Conventional anatomic imaging techniques such as CT scanning are alsonot good at predicting survival following treatment despite tumorshrinkage following therapy. In a recent study involving 56 NSCLCpatients receiving treatment with concurrent cisplatin-basedchemo/radiotherapy or radiotherapy alone for advanced disease, responseby conventional CT imaging did not correlate with survival. MacManus MP, Hicks R J, Wada M, Hoff A, Matthews J, Wirth A, Rischin D, Ball D L.Early F-18FDG-PET response to radical chemoradiotherapy correlatesstrongly with survival in unresectable non-small cell lung cancer. ProcASCO 19:483a, 2000. Response by FDG-PET scans, however, did correlatestrongly with survival (p=0.0006). Survival from the date of a follow-upPET scan was 84% and 84% at 1 and 2 years respectively for 24 patientswho had achieved a complete response on PET, but only 43% and 31% of the32 patients who did not (p=0.010). These results corroborate similarfindings reported recently by other authors. Patz E F Jr, Connolly J,Herndon J. Prognostic value of thoracic FDG PET imaging after treatmentfor non-small cell lung cancer. Am J Roentgenology 174(3):769-774, 2000;Vansteenkiste J F, Stroobants S G, Dupont P J, DeLeyn P R, Verbeken E K,Deneffe G J, Mortelmans L A, Demedts M G. Prognostic importance of thestandardized uptake value on (18)F-fluoro-2-deoxy-glucose positronemission tomography scan in non-small cell lung cancer: An analysis of125 cases. J Clin Oncol 17(10):3201-3206, 1999; Ahuja V, Coleman R E,Herndon J, Patz E F Jr. The prognostic significance offluorodexoyglucose positron emission tomography imaging for patientswith non-small cell lung carcinoma. Cancer 83(5):918-924, 1998.

Therefore, a readily available radiopharmaceutical that could accuratelyidentify and potentially treat early metastatic disease in the patientswith NSCLC would have an important impact on patient care, in terms ofboth staging and response to therapy. Although PET imaging proceduresare gaining effectiveness in this area, the cost and inaccessibilityseverely limits its practical application. There remains a need for anaccurate functional imaging technique based upon a tumor-specificfunction that can non-invasively screen the whole body using relativelyinexpensive and widely available imaging devices.

SUMMARY OF THE INVENTION

The present invention generally provides methods and techniques for thedetection and treatment of various cancers. In one preferred embodiment,the present invention provides a method for detecting and locating Lungcancer, Adrenal cancer, Melanoma, Colon cancer, Colorectal cancer,Ovarian cancer, Prostate cancer, Liver cancer, Subcutaneous cancer,Intestinal cancer, Hepatocellular carcinoma, Retinoblastoma, Cervicalcancer in subject that has or is suspected of having cancer. The methodcomprises the steps of:

-   (a) administering a phospholipid ether analog to the subject; and-   (b) determining whether an organ suspected of having cancer of the    subject retains a higher level of the analog than surrounding    region(s) wherein a higher retention region indicates detection and    location of the cancer. In this method, the phospholipid analog is    selected from:

where X is selected from the group consisting of radioactive isotopes ofiodine; n is an integer between 16 and 30; and Y is selected from thegroup comprising

NH₂, N(R)₂, and N(R)₃, wherein R is an alkyl or arylalkyl substituent or

where X is a radioactive isotope of iodine; n is an integer between 16and 30; Y is selected from the group consisting of H, OH, COOH, COOR andOR, and Z is selected from the group consisting of NH₂, N(R)₂, andN(R)₃, wherein R is an alkyl or arylalkyl substituent. In this method, Xis selected from the group of radioactive isotopes of iodine consistingof ¹²²I,¹²³I,¹²⁴I,¹²⁵I, and ¹³¹I. Preferably, in this method, thephospholipid ether is 18-(p-lodophenyl)octadecyl phosphocholine,1-O-[18(p-lodophenypoctadecyl]-1,3-propanediol-3-phosphocholine, or1-O-[18(p-lodophenyl)octadecyl]-2-O-methyl-rac-glycero-3-phosphocholine,wherein iodine is in the form of a radioactive isotope.

In another embodiment, the present invention provides a method for thetreatment of cancer in a subject. The method comprises administering tothe subject an effective amount of a molecule comprising a phospholipidether analog, as described above. In this method, the cancer is selectedfrom a group consisting of Lung cancer, Adrenal cancer, Melanoma, Coloncancer, Colorectal cancer, Ovarian cancer, Prostate cancer, Livercancer, Subcutaneous cancer, Intestinal cancer, Hepatocellularcarcinoma, Retinoblastoma, Cervical cancer, Glioma, Breast cancer,Pancreatic cancer, Carcinosarcoma and Prostrate cancer.

The present invention also contemplates the use of a phospholipid etheranalog for the production of a pharmaceutical composition for thetreatment of cancer. These phospholipid analogs are selected from thegroup discussed above.

Yet another embodiment of the present invention provides a method ofdifferentiating inflammation, adenoma and hyperplasia from neoplasia ina subject. The method comprises the steps of:

-   -   (a) administering a phospholipid ether analog to the subject;        and    -   (b) determining whether an organ suspected of having        inflammation, adenoma, hyperplasia or neoplasia of the subject        retains a higher level of the analog than surrounding region(s).        When the subject exhibits a higher retention region, it        indicates detection and location of the neoplasia and when the        subject exhibits a lower retention region, it indicates the        presence of an organ suspected of having the adenoma,        hyperplasia or inflammation.

Another embodiment of the present invention provides a method ofdetecting neoplasia in a tissue sample having a phospholipase D (PLD).The method comprises the step of:

(a) quantifying the PLD protein activity level or the PLD mRNA level inthe tissue sample; and

(b) determining whether the tissue sample has a lower level of proteinactivity than surrounding tissue region(s) wherein a lower activityregion indicates detection and location of the neoplasia, or

(c) determining whether the tissue sample has a lower level of mRNA thansurrounding tissue region(s) wherein a lower mRNA level region indicatesdetection and location of the neoplasia.

In this method, the PLD protein activity or the mRNA level may bequantified by contacting the tissue sample with a PLE analog, asdescribed above.

Yet another embodiment of the present invention provides an anti-tumoragent selected by a method of screening a tissue sample having a PLD,comprising the step of: (a) quantifying the PLD protein activity or PLDmRNA level, wherein reduced PLD protein activity or reduced mRNA levelcompared to the surrounding tissue region(s) is indicative of neoplasia.The PLD protein activity or the mRNA level may be quantified bycontacting the tissue sample with a PLE analog, as described above.

Other objects and advantages of the present invention will be apparentfrom the detailed description, drawings and claims accompanying thespecification

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1. PLE Tumor Cell Imaging Hypothesis.

FIG. 2. Scintigraphy of the anterior chest of Patient 03 acquired at 1,2, and 6 days after IV administration of 1 mCi ¹³¹I-NM324. Uptake isseen in the left lingular lung cancer (T) with increasingtumor-to-background ratios over time.

FIG. 3. Structures of PLE analogs.

FIG. 3A. A NM404 analog.

FIG. 4. Comparison of NM324 and NM404 in SCID mouse A549 lung tumormodel following IV administration. Note that most of the NM324 activityis found in the gut and not in the tumor (implanted in the thigh)whereas NM404 identified one tumor in each thigh.

FIG. 4A. Scintigraphic NM404 images of Dunning R3327 metastatic prostatetumors in a Copenhagen rat with primary tumor site (leg) surgicallyremoved. Two lymph node tumors were verified post mortem.

FIG. 6. Digital Photo (A) of excised CT-26 tumor (T) and left and rightlymph nodes (LN). Bioscan image (B) and fused photo/Bioscan image (C)showing correlation of radioactivity in tumor.

FIG. 7. MicroCT images of live mouse of FIG. 6 showing size and locationof CT-26 tumor (arrows). 3D-surface rendered and planer slice images (A,B) as well as coronal (C) and axial (D) slices (40 μm thickness).

FIG. 8. Histologic section (H&E) of normal (left) and RF-ablated (right)CT-26 tumor. Ablated section has lost membrane integrity and appearspyknotic.

FIG. 9. Fused in vivo Bioscan/digital photo image of c-myc pancreatictumor mouse 4 days post ¹²⁵I-NM404 injection (A). Ex vivo image ofexcised tumors (B) for comparison with digital photo (C). Color rangesame as in FIG. 10.

FIG. 10. Bioscan images of c-myc pancreatic tumor mouse 4-days post¹²⁵I-NM404 administration. In vivo image (A) compared with digital photoof dissected mouse (B) showing presence of a large (2 cm) pancreatictumor (T). Three tumors were excised and the remaining carcass scanned(C). The excised tumors were scanned (D) for comparison with digitalphoto (E). Color scale ranges from 0 (black) to 40 (white) cpm.

FIG. 11. MicroCT axial scans of pancreatic tumor-bearing mice. Two largetumors (T) are easily seen in the axial image in panel A. Image of adifferent mouse in B depicts a pancreatic tumor (arrow) located adjacentto the spleen. In mice, the pancreas is a ubiquitous tissue. A digitalphoto of the excised spleen and attached tumor is shown in 11 C forcomparison.

FIG. 12. Bioscan image (4 days after IV injection of ¹²⁵I-NM404) of shamcontrol rat brain (A) and same Bioscan image superimposed over thecorresponding digital photograph of excised rat brain showing lowbackground level of NM404 in normal brain tissue.

FIG. 13. Digital photograph (A) and corresponding Bioscan image ofexcised C6-glioma bearing rat brain (B) 4 days after IV injection of¹²⁵I-NM404. Position and size-matched fused Bioscan image and photograph(C) indicates intense localization of NM404 in tumor. The presence oftumor was histologically confirmed in H&E stained sample in D.

FIG. 14. Coronal microCT scan (left) and dorsal Bioscan image (right) ofa TGFα hepatoma-bearing mouse 10 days post ¹²⁵I-NM404 injection. Liveris enhanced on microCT image with ITG, a hepatocyte-selective CTcontrast agent (Tumor=T).

FIG. 15. Photograph (A) and Bioscan image (B) of excised CT-26tumor-bearing mouse liver 7 days post NM404 injection. Liver tumorinvolvement was extensive. Tumor implant occurred 15 days prior to thisscan. Bioscan image (C) and photograph (D) of excised dissected tumors(T) and normal uninvolved liver (L).

FIG. 16. MicroCT of same mouse presented in FIG. 15 showing the presenceof multiple CT26 tumors. Liver was enhanced using ITG, ahepatocyte-selective contrast agent. These images were acquired 10 dayspost tumor cell implantation and 5 days prior to the Bioscan imagesabove. (Tumors depicted by arrows and gall bladder=GB).

FIG. 17. NM404 Bioscan images of Min mouse with spontaneous rightaxillary mammary tumor (10 mm dia) at various times following IVadministration of ¹²⁵I-NM404 (15 μCi). Coronal microCT image(non-contrast-enhanced) is shown for anatomic comparison (left panel,T=tumor).

FIG. 18. Carmine stained photographs (A,C) and Bioscan images (B,D) ofexcised left and right abdominal mammary glands. Note 2 mm tumor inpanel A (T) which is easily detected in Bioscan Image (B) of the leftgland. Lymph node (small arrow in A) shows no uptake of NM404. No tumorswere visually detected in the right gland (C, D). Photograph (E) andBioscan image (F) of colon indicates no uptake of NM404 in adenomatouspolyps (arrows).

FIG. 19. MicroCT scans of Min mouse of FIG. 18. Panel A is a low densitysurface rendering showing a large left axillary mammary tumor. Panel Bis the high density surface rendering after blood pool CT contrast agentBP10 was administered to help locate tumor feeder vessels. Panel C is acomposite coronal CT image and high density surface rendering showingabsolute feeder vessel localization. Orientation is from beneath inpanel C, whereas Panels A and B are viewed from above.

FIG. 20. NM404 Bioscan images of Min mouse with spontaneous rightaxillary mammary adenocarcinoma (10 mm dia) at various times followingIV administration of 125I-NM404 (15 μCi). Coronal microCT image(non-contrast-enhanced) is shown for anatomic comparison (left panel,T=tumor).

FIG. 21. Bioscan image of excised mammary glands (A) and colon (E) froman FVBxB6Min mouse 8 days post NM404 administration. Correspondingdigital photo of same excised tissues in B and D, respectively. Carminestained enlarged photograph (C) shows the presence of hyperplasias(arrows) but no corresponding focal activity in the Bioscan Image (A).Tumor uptake on Bioscan image (A) corresponds to larger adenocarcinomain B. Photograph (D) and Bioscan image (E) of excised colon indicates nouptake of NM404 in adenomatous polyps (arrows).

FIG. 22. MicroCT scans of Min mouse shown in FIG. 21. Panel A is a lowdensity surface rendering showing a large left axial mammary tumor.Panel B is the high density surface rendering after blood pool CTcontrast agent BP10 was administered to help locate tumor feedervessels. Panel C is a composite coronal CT image and high densitysurface rendering showing absolute feeder vessel localization.Orientation is from beneath in panel C, whereas Panels A and B areviewed from above.

FIG. 23. Comparison of ¹²⁵I-NM404 (A&B) and NM324 (C&D) uptake inexcised SCID mouse lungs containing A549 lung CA micromets (<1 mm dia).

FIG. 24. Enzymatic Metabolism of PLE's.

FIG. 25. Time to first tumor in ENU-treated Min/+ mice. Time to firstmammary tumor expressed as days after ENU. Female Min/+ mice weretreated with ENU and checked twice weekly for the presence of mammarytumors. The time after ENU treatment to first tumor is plotted in 5 dayintervals for B6Min/+ (n=45)(□), BRB6 Min/+ (n=18)(Δ), FVBB6 Min/+(n=18) (⋄).

FIG. 26. Bioscan images of prone FVBxB6 min mouse 1 (A) and 7 (B) dayspost ¹²⁵I-NM404 administration indicates presence of large axillarymammary tumor. Bioscan image of excised mammary gland (C) 10 days afterinjection shows incorporation of NM404 in large 10 mm adenocarcinoma andsmaller adjacent 2 mm tumor that wasn't visible in the in vivo scan.

FIG. 27. MicroCT images of same FVBxB6 min mouse, as shown in FIG. 26,showing large axillary mammary tumor. Coronal and axial slices are shownin A and B, whereas 3D-surface (gold) and coronal slices are displayedsimultaneously in posterior (C) and anterior (D) views.

FIG. 28. Apparent SCC1 and 6 Tumor Regression after Injection of¹²⁵I-NM404.

FIG. 29. Patient 1 gamma cameral images (left panel) at 4 and 11 daysfollowing ¹³¹I-NM404 injection showing intense and prolonged retentionof the agent in both NSCLC tumors (arrows). Axial CT scans (right panel)showing location and size of focal 3 cm lesion in left lung (A) andlarge infiltrative mass in right lung (B) (arrows).

FIG. 30. Patient 2 anterior and posterior whole body planar nuclearmedicine images (left panel) following iv administration of ¹³¹I-NM404.Axial (A) and coronal (B) CT scans (right panel) showing location oflarge 6 cm NSCLC (arrows).

I. GENERAL DESCRIPTION OF THE INVENTION

General Description of the Invention: Before the present methods aredescribed, it is understood that this invention is not limited to theparticular methodology, protocols, cell lines, and reagents described,as these may vary. It is also to be understood that the terminology usedherein is for the purpose of describing particular embodiments only, andis not intended to limit the scope of the present invention which willbe limited only by the appended claims.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural reference unless thecontext clearly dictates otherwise. Thus, for example, reference to “acell” includes a plurality of such cells and equivalents thereof knownto those skilled in the art, and so forth. As well, the terms “a” (or“an”), “one or more” and “at least one” can be used interchangeablyherein. It is also to be noted that the terms “comprising”, “including”,and “having” can be used interchangeably.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present invention, the preferred methodsand materials are now described. All publications mentioned herein areincorporated herein by reference for the purpose of describing anddisclosing the chemicals, cell lines, vectors, animals, instruments,statistical analysis and methodologies which are reported in thepublications which might be used in connection with the invention.Nothing herein is to be construed as an admission that the invention isnot entitled to antedate such disclosure by virtue of prior invention.

As defined herein, the term “isomer” includes, but is not limited tooptical isomers and analogs, structural isomers and analogs,conformational isomers and analogs, and the like. In one embodiment,this invention encompasses the use of different optical isomers of ananti-tumor compound of Formula 3A. It will be appreciated by thoseskilled in the art that the anti-tumor compounds useful in the presentinvention may contain at least one chiral center. Accordingly, thecompounds used in the methods of the present invention may exist in, andbe isolated in, optically-active or racemic forms. Some compounds mayalso exhibit polymorphism.

It is to be understood that the present invention may encompass the useof any racemic, optically-active, polymorphic, or stereroisomeric form,or mixtures thereof, which form possesses properties useful in thetreatment of tumor-related conditions described and claimed herein. Inone embodiment, the anti-tumor compounds may include pure (R)-isomers.In another embodiment, the anti-tumor compounds may include pure(S)-isomers. In another embodiment, the compounds may include a mixtureof the (R) and the (S) isomers. In another embodiment, the compounds mayinclude a racemic mixture comprising both (R) and (S) isomers. It iswell known in the art how to prepare optically-active forms (forexample, by resolution of the racemic form by recrystallizationtechniques, by synthesis from optically-active starting materials, bychiral synthesis, or by chromatographic separation using a chiralstationary phase).

The invention includes the use of pharmaceutically acceptable salts ofamino-substituted compounds with organic and inorganic acids, forexample, citric acid and hydrochloric acid. The invention also includesN-oxides of the amino substituents of the compounds described herein.Pharmaceutically acceptable salts can also he prepared from the phenoliccompounds by treatment with inorganic bases, for example, sodiumhydroxide. Also, esters of the phenolic compounds can be made withaliphatic and aromatic carboxylic acids, for example, acetic acid andbenzoic acid esters. As used herein, the term “pharmaceuticallyacceptable salt” refers to a compound formulated from a base compoundwhich achieves substantially the same pharmaceutical effect as the basecompound.

This invention further includes method utilizing derivatives of theanti-tumor compounds. The term “derivatives” includes but is not limitedto ether derivatives, acid derivatives, amide derivatives, esterderivatives and the like. In addition, this invention further includesmethods utilizing hydrates of the anti-tumor compounds. The term“hydrate” includes but is not limited to hemihydrate, monohydrate,dihydrate, trihydrate and the like.

This invention further includes methods of utilizing metabolites of theanti-tumor compounds. The term “metabolite” means any substance producedfrom another substance by metabolism or a metabolic process.

As defined herein, “contacting” means that the anti-tumor compound usedin the present invention is introduced into a sample containing thereceptor in a test tube, flask, tissue culture, chip, array, plate,microplate, capillary, or the like, and incubated at a temperature andtime sufficient to permit binding of the anti-tumor compound to areceptor. Methods for contacting the samples with the anti-tumorcompound or other specific binding components are known to those skilledin the art and may be selected depending on the type of assay protocolto be run. Incubation methods are also standard and are known to thoseskilled in the art.

In another embodiment, the term “contacting” means that the anti-tumorcompound used in the present invention is introduced into a patientreceiving treatment, and the compound is allowed to come in contact invivo.

As used herein, the term “treating” has a commonly understood meaning ofadministration of a remedy to a patient who has or is suspected ofhaving a disease or a condition. As used herein, the terms “reducing”,“suppressing” and “inhibiting” have their commonly understood meaning oflessening or decreasing. As used herein, the term “progression” meansincreasing in scope or severity, advancing, growing or becoming worse.As used herein, the term “recurrence” means the return of a diseaseafter a remission.

As used herein, the term “administering” refers to bringing a patient,tissue, organ or cells in contact with an anti-tumor phospholipid ethercompound. As used herein, administration can be accomplished in vitro,i.e. in a test tube, or in vivo, i.e. in cells or tissues of livingorganisms, for example, humans. In certain embodiments, the presentinvention encompasses administering the compounds useful in the presentinvention to a patient or subject. A “patient” or “subject”, usedequivalently herein, refers to a mammal, preferably a human, thateither: (1) has a disorder remediable or treatable by administration ofthe anti-tumor substance using a phospholipid ether compound or (2) issusceptible to a disorder that is preventable by administering theanti-tumor compound using a phospholipid ether compound

As used herein, “pharmaceutical composition” means therapeuticallyeffective amounts of the anti-tumor compound together with suitablediluents, preservatives, solubilizers, emulsifiers, and adjuvants,collectively “pharmaceutically-acceptable carriers.” As used herein, theterms “effective amount” and “therapeutically effective amount” refer tothe quantity of active therapeutic agent sufficient to yield a desiredtherapeutic response without undue adverse side effects such astoxicity, irritation, or allergic response. The specific “effectiveamount” will, obviously, vary with such factors as the particularcondition being treated, the physical condition of the patient, the typeof animal being treated, the duration of the treatment, the nature ofconcurrent therapy (if any), and the specific formulations employed andthe structure of the compounds or its derivatives. In this case, anamount would be deemed therapeutically effective if it resulted in oneor more of the following: (a) the prevention of disease (e.g.,pancreatic cancer, breast cancer); and (b) the reversal or stabilizationof such disease. The optimum effective amounts can be readily determinedby one of ordinary skill in the art using routine experimentation.

Pharmaceutical compositions are liquids or lyophilized or otherwisedried formulations and include diluents of various buffer content (e.g.,Tris-HCl, acetate, phosphate), pH and ionic strength, additives such asalbumin or gelatin to prevent absorption to surfaces, detergents (e.g.,Tween (Polysorbate) 20, Tween 80, Pluronic F68, bile acid salts),solubilizing agents (e.g., glycerol, polyethylene glycerol),anti-oxidants (e.g., ascorbic acid, sodium metabisulfite), preservatives(e.g., Thimerosal, benzyl alcohol, parabens), bulking substances ortonicity modifiers (e.g., lactose, mannitol), covalent attachment ofpolymers such as polyethylene glycol to the protein, complexation withmetal ions, or incorporation of the material into or onto particulatepreparations of polymeric compounds such as polylactic acid, polglycolicacid, hydrogels, etc, or onto liposomes, microemulsions, micelles,unilamellar or multilamellar vesicles, erythrocyte ghosts, orspheroplasts. Such compositions will influence the physical state,solubility, stability, rate of in vivo release, and rate of in vivoclearance. Controlled or sustained release compositions includeformulation in lipophilic depots (e.g., fatty acids, waxes, oils).

Also encompassed by the invention are methods of administeringparticulate compositions coated with polymers (e.g., poloxamers orpoloxamines). Other embodiments of the compositions incorporateparticulate forms protective coatings, protease inhibitors or permeationenhancers for various routes of administration, including topical,parenteral, pulmonary, nasal and oral. In one embodiment thepharmaceutical composition is administered parenterally, paracancerally,transmucosally, tansdermally, intramuscularly, intravenously,intradermally, subcutaneously, intraperitonealy, intraventricularly,intracranially and intratumorally.

Further, as used herein “pharmaceutically acceptable carriers” are wellknown to those skilled in the art and include, but are not limited to,0.01-0.1M and preferably 0.05M phosphate buffer or 0.9% saline.Additionally, such pharmaceutically acceptable carriers may be aqueousor non-aqueous solutions, suspensions, and emulsions. Examples ofnon-aqueous solvents are propylene glycol, polyethylene glycol,vegetable oils such as olive oil, and injectable organic esters such asethyl oleate. Aqueous carriers include water, alcoholic/aqueoussolutions, emulsions or suspensions, including saline and bufferedmedia.

Parenteral vehicles include sodium chloride solution, Ringer's dextrose,dextrose and sodium chloride, lactated Ringer's and fixed oils.Intravenous vehicles include fluid and nutrient replenishers,electrolyte replenishers such as those based on Ringer's dextrose, andthe like. Preservatives and other additives may also be present, suchas, for example, antimicrobials, antioxidants, collating agents, inertgases and the like.

Controlled or sustained release compositions administerable according tothe invention include formulation in lipophilic depots (e.g. fattyacids, waxes, oils). Also comprehended by the invention are particulatecompositions coated with polymers (e.g. poloxamers or poloxamines) andthe compound coupled to antibodies directed against tissue-specificreceptors, ligands or antigens or coupled to ligands of tissue-specificreceptors.

Other embodiments of the compositions administered according to theinvention incorporate particulate forms, protective coatings, proteaseinhibitors or permeation enhancers for various routes of administration,including parenteral, pulmonary, nasal and oral.

Compounds modified by the covalent attachment of water-soluble polymerssuch as polyethylene glycol, copolymers of polyethylene glycol andpolypropylene glycol, carboxymethyl cellulose, dextran, polyvinylalcohol, polyvinylpyrrolidone or polyproline are known to exhibitsubstantially longer half-lives in blood following intravenous injectionthan do the corresponding unmodified compounds (Abuchowski et al., 1981;Newmark et al., 1982; and Katre et al., 1987). Such modifications mayalso increase the compound's solubility in aqueous solution, eliminateaggregation, enhance the physical and chemical stability of thecompound, and greatly reduce the immunogenicity and reactivity of thecompound. As a result, the desired in vivo biological activity may beachieved by the administration of such polymer-compound abducts lessfrequently or in lower doses than with the unmodified compound.

In yet another method according to the invention, a pharmaceuticalcomposition can be delivered in a controlled release system. Forexample, the agent may be administered using intravenous infusion, animplantable osmotic pump, a transdermal patch, liposomes, or other modesof administration. In one embodiment, a pump may be used (see Langer,supra; Sefton, CRC Crit. Ref. Biomed. Eng. 14:201 (1987); Buchwald etal., Surgery 88:507 (1980); Saudek et al., N. Engl. J. Med. 321:574(1989). In another embodiment, polymeric materials can be used. In yetanother embodiment, a controlled release system can be placed inproximity to the therapeutic target, for example liver, thus requiringonly a fraction of the systemic dose (see, e.g., Goodson, in MedicalApplications of Controlled Release, supra, vol. 2, pp. 15-138 (1984).Other controlled release systems are discussed in the review by Langer(Science 249:1527-1533 (1990).

The pharmaceutical preparation can comprise the anti-tumor compoundalone, or can further include a pharmaceutically acceptable carrier, andcan be in solid or liquid form such as tablets, powders, capsules,pellets, solutions, suspensions, elixirs, emulsions, gels, creams, orsuppositories, including rectal and urethral suppositories.Pharmaceutically acceptable carriers include gums, starches, sugars,cellulosic materials, and mixtures thereof. The pharmaceuticalpreparation containing the anti-tumor compound can be administered to apatient by, for example, subcutaneous implantation of a pellet. In afurther embodiment, a pellet provides for controlled release ofanti-tumor compound over a period of time. The preparation can also beadministered by intravenous, intra-arterial, or intramuscular injectionof a liquid preparation oral administration of a liquid or solidpreparation, or by topical application. Administration can also beaccomplished by use of a rectal suppository or a urethral suppository.

The pharmaceutical preparations administerable by the invention can beprepared by known dissolving, mixing, granulating, or tablet-formingprocesses. For oral administration, the anti-tumor compounds or theirphysiologically tolerated derivatives such as salts, esters, N-oxides,and the like are mixed with additives customary for this purpose, suchas vehicles, stabilizers, or inert diluents, and converted by customarymethods into suitable forms for administration, such as tablets, coatedtablets, hard or soft gelatin capsules, aqueous, alcoholic or oilysolutions. Examples of suitable inert vehicles are conventional tabletbases such as lactose, sucrose, or cornstarch in combination withbinders such as acacia, cornstarch, gelatin, with disintegrating agentssuch as cornstarch, potato starch, alginic acid, or with a lubricantsuch as stearic acid or magnesium stearate.

Examples of suitable oily vehicles or solvents are vegetable or animaloils such as sunflower oil or fish-liver oil. Preparations can beeffected both as dry and as wet granules. For parenteral administration(subcutaneous, intravenous, intra-arterial, or intramuscular injection),the anti-tumor compounds or their physiologically tolerated derivativessuch as salts, esters, N-oxides, and the like are converted into asolution, suspension, or expulsion, if desired with the substancescustomary and suitable for this purpose, for example, solubilizers orother auxiliaries. Examples are sterile liquids such as water and oils,with or without the addition of a surfactant and other pharmaceuticallyacceptable adjuvants. Illustrative oils are those of petroleum, animal,vegetable, or synthetic origin, for example, peanut oil, soybean oil, ormineral oil. In general, water, saline, aqueous dextrose and relatedsugar solutions, and glycols such as propylene glycols or polyethyleneglycol are preferred liquid carriers, particularly for injectablesolutions.

The preparation of pharmaceutical compositions which contain an activecomponent is well understood in the art. Such compositions may beprepared as aerosols delivered to the nasopharynx or as injectables,either as liquid solutions or suspensions; however, solid forms suitablefor solution in, or suspension in, liquid prior to injection can also beprepared. The preparation can also be emulsified. The active therapeuticingredient is often mixed with excipients which are pharmaceuticallyacceptable and compatible with the active ingredient. Suitableexcipients are, for example, water, saline, dextrose, glycerol, ethanol,or the like or any combination thereof.

In addition, the composition can contain minor amounts of auxiliarysubstances such as wetting or emulsifying agents, pH buffering agentswhich enhance the effectiveness of the active ingredient.

An active component can be formulated into the composition asneutralized pharmaceutically acceptable salt forms. Pharmaceuticallyacceptable salts include the acid addition salts, which are formed withinorganic acids such as, for example, hydrochloric or phosphoric acids,or such organic acids as acetic, oxalic, tartaric, mandelic, and thelike. Salts formed from the free carboxyl groups can also be derivedfrom inorganic bases such as, for example, sodium, potassium, ammonium,calcium, or ferric hydroxides, and such organic bases as isopropylamine,trimethylamine, 2-ethylamino ethanol, histidine, procaine, and the like.

For topical administration to body surfaces using, for example, creams,gels, drops, and the like, the anti-tumor compounds or theirphysiologically tolerated derivatives such as salts, esters, N-oxides,and the like are prepared and applied as solutions, suspensions, oremulsions in a physiologically acceptable diluent with or without apharmaceutical carrier.

In another method according to the invention, the active compound can bedelivered in a vesicle, in particular a liposome (see Langer, Science249:1527-1533 (1990); Treat et al., in Liposomes in the Therapy ofInfectious Disease and Cancer, Lopez-Berestein and Fidler (eds.), Liss,N.Y., pp. 353-365 (1989); Lopez-Berestein ibid., pp. 317-327; seegenerally ibid).

For use in medicine, the salts of the anti-tumor compound may bepharmaceutically acceptable salts. Other salts may, however, be usefulin the preparation of the compounds according to the invention or oftheir pharmaceutically acceptable salts. Suitable pharmaceuticallyacceptable salts of the compounds include acid addition salts which may,for example, be formed by mixing a solution of the compound according tothe invention with a solution of a pharmaceutically acceptable acid suchas hydrochloric acid, sulphuric acid, methanesulphonic acid, fumaricacid, maleic acid, succinic acid, acetic acid, benzoic acid, oxalicacid, citric acid, tartaric acid, carbonic acid or phosphoric acid.

Generally, NM404 is a promising new tumor-selective diagnostic imagingagent to monitor the treatment response of several tumor treatmentmodalities. Radioiodinated NM404, a second-generation phospholipid etheranalog, had displayed remarkable tumor selectivity in 10/10 xenografttumor models and more recently in another 14/14 spontaneous rodent tumormodels. Due to a lack of metabolic phospholipase enzymes in themembranes of tumor cells, the prevailing hypothesis of this approach isthat phospholipid ether analogs become trapped exclusively in tumor cellmembranes because of their inability to become metabolized andeliminated. Thus, the differential clearance rates of phospholipidethers from normal cells versus viable tumor cells form the basis ofthis concept. Results obtained in a variety tumor models indicate thatNM404 is sequestered and selectively retained by viable tumor cells andlocalizes in both primary and metastatic lesions regardless of anatomiclocation including those found in lymph nodes. Unlike FDG, this agentdoes not localize in infectious sites. Other advantages of NM404 overFDG include the following: NM404 is selective for and retainedindefinitely by malignant tumor cells whereas FDG in not selective fortumor cells and goes to infectious sites and hyperplasias (Barret'sEsophagus). Further, since ¹²⁴I has a 4 day physical half life it can beshipped anywhere in the world whereas FDG with its 110 min half-life,may have limited distribution within 200 miles of the production site.NM404 undergoes prolonged retention (not metabolized) and thereforeaffords a significant therapeutic potential when mated with anappropriate radioisotope like ¹³¹I whereas FDG does not possess anytherapeutic potential. NM404 can be labeled with a variety of iodineisotopes expanding it versatility (diagnosis and therapy as well as atool for experimental animal studies) whereas FDG is limited to ¹⁸F forPET scanning or potentially ¹⁹F (stable) for magnetic resonance imagingalbeit at very low sensitivity levels. Regardless of its tumor targetingability, due to its rapid metabolism in tumor cells, it has notpotential for therapy. NM404 affords the potential to not onlyaccurately predict local tumor response to various treatment modalities,but also allows detection of distant metastatic lesions in cases ofsub-therapeutic primary tumor treatment.

II. THE INVENTION

The present invention generally provides methods and techniques for thedetection and treatment of various cancers. In one preferred embodiment,the present invention provides a method for detecting and locating Lungcancer, Adrenal cancer, Melanoma, Colon cancer, Colorectal cancer,Ovarian cancer, Prostate cancer, Liver cancer, Subcutaneous cancer,Intestinal cancer, Hepatocellular carcinoma, Retinoblastoma, Cervicalcancer in subject that has or is suspected of having cancer. The methodcomprises the steps of:

-   -   (a) administering a phospholipid ether analog to the subject;        and    -   (b) determining whether an organ suspected of having cancer of        the subject retains a higher level of the analog than        surrounding region(s) wherein a higher retention region        indicates detection and location of the cancer. In this method,        the phospholipid analog is selected from:

where X is selected from the group consisting of radioactive isotopes ofiodine; n is an integer between 16 and 30; and Y is selected from thegroup comprising NH₂, N(R)₂. N(R)₃, wherein R is an alkyl or arylalkylsubstituent or

where X is a radioactive isotope of iodine; n is an integer between 16and 30; Y is selected from the group consisting of H, OH, COOH, COOR andOR, and Z is selected from the group consisting of NH₂, N(R)₂, andN(R)₃, wherein R is an alkyl or aralkyl substituent. In this method, Xis selected from the group of radioactive isotopes of iodine consistingof ¹²²I, ¹²³I, ¹²⁴I,¹²⁵I, and ¹³¹I. Preferably, in this method, thephospholipid ether is 18-(p-lodophenyl)octadecyl phosphocholine,1-O-[18(p-lodophenyl)octadecyl]-1,3-propanediol-3-phosphocholine, or1-O-[18(p-lodophenyl)octadecyl]-2-O-methyl-rac-glycero-3-phosphocholine,wherein iodine is in the form of a radioactive isotope. Variousphospholipid ethers and related methodologies for the manufacture anduse of the phospholipid ether compounds are described in U.S. Pat. Nos.4,925,649; 4,965,391; 5,087,721; 5,347,030; 6,255,519 and 6,417,384 andall of which are herein incorporated by reference.

In another embodiment, the present invention provides a method for thetreatment of cancer in a subject. The method comprises administering tothe subject an effective amount of a molecule comprising a phospholipidether analog, as described above. In this method, the cancer is selectedfrom a group consisting of Lung cancer, Adrenal cancer, Melanoma, Coloncancer, Colorectal cancer, Ovarian cancer, Prostate cancer, Livercancer, Subcutaneous cancer, Intestinal cancer, Hepatocellularcarcinoma, Retinoblastoma, Cervical cancer, Glioma, Breast cancer,Pancreatic cancer, carcinosarcoma and Prostrate cancer.

The present invention also contemplates the use of a phospholipid etheranalog for the production of a pharmaceutical composition for thetreatment of cancer. These phospholipid analogs are selected from thegroup discussed above.

Yet another embodiment of the present invention provides a method ofdifferentiating inflammation, adenoma, hyperplasia from neoplasia in asubject. The method comprises the steps of:

-   -   (a) administering a phospholipid ether analog to the subject;        and    -   (b) determining whether an organ suspected of having        inflammation, adenoma, hyperplasia or neoplasia of the subject        retains a higher level of the analog than surrounding region(s).        When the subject exhibits a higher retention region, it        indicates detection and location of the neoplasia and when the        subject exhibits a lower retention region, it indicates the        presence of an organ suspected of having the adenoma,        hyperplasia or inflammation.

Another embodiment of the present invention provides a method ofdetecting neoplasia in a tissue sample having a phospholipase D (PLD).The method comprises the step of:

(a) quantifying the PLD protein activity level or the PLD mRNA level inthe tissue sample; and

(b) determining whether the tissue sample has a lower level of proteinactivity than surrounding tissue region(s) wherein a lower activityregion indicates detection and location of the neoplasia, or

(c) determining whether the tissue sample has a lower level of mRNA thansurrounding tissue region(s) wherein a lower mRNA level region indicatesdetection and location of the neoplasia.

In this method, the PLD protein activity or the mRNA level may bequantified by contacting the tissue sample with a PLE analog, asdescribed above.

Yet another embodiment of the present invention provides an anti-tumoragent selected by a method of screening a tissue sample having a PLD,comprising the step of: (a) quantifying the PLD protein activity or PLDmRNA level, wherein reduced PLD protein activity or reduced mRNA levelcompared to the surrounding tissue region(s) is indicative of neoplasia.The PLD protein activity or the mRNA level may be quantified bycontacting the tissue sample with a PLE analog, as described above.

The following sections discuss the use and methods related to onlycertain phospholipid ether compounds, however, such uses are exemplaryand should not be deemed to narrow the scope of the present invention.

For example, NM404 a phospholipid ether has demonstrated markedspecificity for neoplastic tissue but not in preneoplastic tissue inmany experimental tumor models. The high tumor to background avidity andtumor selectivity of NM404 suggests it may be potentially superior to¹⁸F-FDG PET scanning for intra-treatment tumor imaging. The precisemechanism of tumor specificity of NM404 is under investigation, andcurrently is not as well described as the glucose utilization mechanismfor ¹⁸F-FDG uptake. It is not well established whether NM404 uptake inneoplastic tissue depends on the viability of that tissue, or if thisuptake phenomenon is related to some membrane or matrix component thatis independent of tissue viability. If this uptake and specificity arelinked to tumor viability, it would follow that NM404 uptake in tumorsrecently sterilized by radiation would be non existent or poor, whereastumors resistant to radiation would show continued uptake. Recently,Inventors demonstrated NM404 uptake and killing in both radio sensitiveand radio resistant squamous cancer cells (SCC1 and 6) in nude mice.Such an assay would be invaluable in managing patients treated withradiation therapy since patients manifesting no post-treatment NM404localization would indicate cure, whereas those with resistant tumors(continued uptake of NM404) could be offered other non-radiation options(surgery, chemotherapy, etc).

One approach to the development of sensitive, more available imagingexams is to design carrier molecules which are capable of selectivelydelivering a radiopharmaceutical probe to the desired target tissue. Theinventors approach has been to capitalize on unique biochemical orpharmacological properties of molecules displaying a high degree oftissue or tumor selectivity.

Snyder and coworkers^(16,17) observed that a variety of animal and humantumor cells contain much higher concentrations of naturally occurringether lipids in the cell membranes than normal tissue. He proposed thatthe accumulation of ether lipids in tumors was a result of a lowercapacity of tumor cells to metabolize these lipids due to a lack of keymetabolic enzymes. The inventors have capitalized on this observation bysynthesizing a number of radioiodinated phospholipid ether (PLE) analogsas potential tumor-selective imaging agents. Several of these PLEanalogs have exhibited a striking and apparently universal ability tolocalize in and be selectively retained by a wide variety of spontaneousand transplanted rat, murine, and human tumor models (24/24).

The inventors prevailing hypothesis (FIG. 1) is that phospholipid ethersbecome trapped in viable tumor cell membranes because of their inabilityto become metabolized and eliminated. Extraction of tumors followingadministration of radioiodinated phospholipid ethers showed the presenceof only the intact agent, whereas analysis of the urine and fecesrevealed only metabolites. Thus, it is the differential clearance ratesof phospholipid ethers from normal cells versus tumor cells that formthe basis of this concept. Preliminary results obtained in over 24xenograft and spontaneous tumor models have universally shown NM404 toundergo selective uptake and prolonged retention in tumors. Because theagent is metabolized to some extent in the liver, the inventors avoidedearlier compound evaluation in liver tumor models due to high liverbackground radioactivity levels. Further, because NM404 affords lowerliver background levels than its predecessors, the inventors expandedevaluation into liver tumors in light of the fact that imaging patientswith HCC has been problematic. Many patients have underlying cirrhosisand therefore it is difficult to distinguish regenerating nodules fromHCC on cross sectional imaging. Moreover, preliminary studies evaluatingPET scanning with FDG have shown only 20-50% sensitivity in detectingthe disease. Verhoef C, Valkema R. et al., Liver (2002) 22:51-56.Further, PET-FDG is not useful in diagnostic screening in brain.Similarly FDG has not useful in evaluating disease in liver due to highnatural uptake by hepatocytes.

Following examples depict preferred embodiments of the present inventionand are for illustrative purposes only. These examples should not bedeemed to narrow the scope of the present invention.

III. EXAMPLES A. Example I Synthesis, Radiolabeling, and Formulation ofNM404

The inventors' synthetic approach was based on the copper-catalyzedcross-coupling reaction of Grignard reagents with alkyl tosylates orhalides for the alkyl chain elongation (see the scheme below). Thesynthesis was started from p-iodobenzyl alcohol 1 which was convertedinto p-iodobenzyl bromide 2 by reaction with trimethylsilyl bromide.p-lodobenzyl bromide 2 was further coupled with Grignard reagent 3 inthe presence of Li₂CuCl₄ as a catalyst. 12-(p-lodophenyl)dodecanol 5obtained after deprotection of the first coupling product 4 wasconverted into tosylate 6. In the next step, tosylate 6 was coupled withGrignard reagent 7 containing 6 carbon atoms and this completed thechain elongation process. THP deprotection of 8 gave18-(p-iodophenyl)octadecanol 9 which was converted into 10 (NM-404) bytwo-step procedure as shown in the scheme.

Further, rapid high yield synthesis process for labeling NM404 with anyisotope if iodine, including ¹²⁴I, ¹²⁵I and ¹³¹I was carried out by thefollowing process:

First, an aluminum heating block apparatus was preheated to 145° C. anda condenser was prepared using a 5 ml disposable syringe barrel fittedwith a bent 1.5 inch 18 ga disposable needle and a rubber septum at thetop.

Second, the HPLC system was initiated and the reservoir was filled withfiltered degassed solvent (hexane/isopropanol/water (40:52:8). Thesystem was equilibrated followed by a systematic check-up of theancillary systems such as the pump, detectors, chart recorders andcomputer integrators.

Third, a 3-mi disposable syringe charcoal trap as prepared by using aglass wool plug in bottom, filling the syringe with 2.5 mL withgranulated charcoal, adding another glass wool plug and inserting aseptum on top. A short tubing adaptor needle was placed on the syringeand an 18-ga needle was inserted through the septum on the top. Thecharcoal trap was connected to the top-of the condenser and vented tothe atmosphere through a sodium thiosulfate trap.

Fourth, 5 mg of ammonium sulfate was added in 20 μl of deionized waterin 2 ml borosilicate glass v-vial followed by 20 μg of unlabeled NM404in 20-μl of absolute ethanol to the vial. The vial was gently swirled orflicked to ensure mixing and 6 borosilicate glass beads (3 mm) were alsoadded to the vial. The vial was then sealed with a Teflon-coated butylrubber septum and an aluminum crimp cap. The septum was punctured withan 18-ga needle and the desired amount of aqueous sodium iodide-131 (in0.1 N NaOH, typically 5 mCi in 15 μl) was added via a Hamiltonmicrosyringe through the septum. The vial was again gently swirled orflicked to ensure mixing. The vial was assayed in a dose calibrator.

Fifth, the charcoal trap syringe was inserted into the reaction vial andthe reaction vial was lowered into the heating block well (filled halfway with sand). The reaction vial was heated at 145° C. for 40 minduring which most of the solvent distilled off and condensed in thecondenser. A stream of air (4×25 ml) was slowly inserted through thereaction vial with a 25-ml syringe. The temperature of the reaction vilewas increased to 155° C. and heating was continued for an additional 30minutes. The reaction vial was removed from the block heater and thecondenser/trap assembly was disconnected and discarded and vial wasallowed to cool to room temperature.

Sixth, 0.5 ml of absolute ethanol was added into the reaction vial. Thevial was gently swirled and assayed in the dose calibrator.

Seventh, a radio-TLC analysis of the crude labeled product mixture wasconducted on silica gel (chloroform/methanol/water (65/35/4).

Eighth, Amberlite IRA 400-OH resin column was prepared by presoaking 1.0g of resin in 5 ml of abs. ethanol for 30 minutes. Ethanol was decantedand the resin was rinsed with two additional 5 ml portions of ethanol.The wet resin was added into a 3 ml disposable syringe barrel with aglass wool plug at the bottom and fitted with an Acrodisc filter and a1-way stopcock. The ethanolic solution of the crude radioiodinatedproduct was gradually eluted through the resin column into a 5 ml vial.

Ninth, a septum was inserted and the solvent was blown off with a streamof nitrogen. A charcoal syringe was attached on the outlet of the vialprior to initiating nitrogen flow. Once dry, 50 μl of ethanol was usedto dilute and transfer contents to a 300 μl v-vial. The source vial wasrinsed with a second 50 μl ethanol wash and transferred to the v-vial.

Tenth, HPLC pump was stabilized and a solvent flow of 1.0 ml/min wasestablished. The reaction mixture was purified by HPLC on a Perkin-Elmercartridge silica column (4.3×33 mm, 3 μm silica) eluted withhexane/isopropanol/water (40:52:8) at 1.0 ml/min. Peak detection wasperformed by UV at 230 and 254 nm and by radioactivity. Once theappropriate peak was collected in a sterile vial, a small sample forradio-TLC analysis was removed and the remaining solvent was evaporatedwith a stream of nitrogen to give the desired compound as a dry residue.Specific activity was calculated as necessary.

Eleventh, Polysorbate 20 was added at a ratio of 0.1 μl/1.0 μg of NM-404to the flask from a stock solution of 5% Polysorbate 20 in absoluteethanol. Polysorbate 20 is the pharmaceutical grade of Tween 20 that isnow used in both human and animal studies with NM404. The solvent wasremoved by rotary evaporation for 10 min at <30° C. The residue wasdissolved with mixing in sufficient sterile water to yield a 2%Polysorbate 20 solution. The formulated product was passed through asterile 0.2 μm Pall-Gelman Acrodisc filter (13 mm) into a dry, sterile,multidose vial (Hollister-Stier) vented with another sterile 0.2 μmfilter. 100 μl of product solution was diverted into a vial for QCanalysis.

Twelfth, radioactivity was measured in the dose calibrator and qualitycontrol tests (sterility, apyrogenicity) were performed.

All unlabeled NM404 were taken from the original stock batch thatrecently underwent acute toxicology testing in order to minimizepotential synthetic differences between studies. Radioiodination ofNM404 was routinely achieved by an isotope exchange reaction in a meltof pivalic acid developed by the inventors¹⁹ or by the new methoddescribed herein and prepared for injection according to standardmethods described by the inventors.²² This procedure was usedeffectively for preparing sterile material for the initial human trialswith NM324, the predecessor of NM404 and has been used over 40 times toprepare ¹²⁵I- and ¹³¹I-labeled NM404. Generally, following purificationand accurate mass quantification by HPLC, the radiopharmaceutical wasdissolved in absolute ethanol (50-500 μl) and Polysorbate 20 (0.1 μl/μgof compound). The ethanol is removed under vacuum and the residuedissolved in sterile water to give a final solution containing no morethan 2-3% Polysorbate 20. Sterilization was achieved by filtrationthrough a sterile 0.2 μm filter unit. Final radiochemical purity mustexceed 97% before using in animals. Quantification and calculation offinal specific activity were achieved by HPLC analysis using known massstandards, and quantification of radioactivity (¹²⁵I) was accomplishedby dilution and counting in a PE Wallac gamma-counter in order to avoidattenuation concerns. Quantification of higher energy isotopes including¹³¹I were done with a dose calibrator with built in settings for theseisotopes. Specific activities of 1 mCi per 100 μg of radioiodinatedNM404 were typically achieved. Injection volumes were typically around100 μl per mouse. Tissue distribution data were expressed as a percentinjected dose (+SEM) per gram of tissue and also as percent injecteddose per organ when whole organs were weighed according to publishedprocedures established by the inventors.²² At each time point,tumor-to-tissue-ratios were calculated on a percent injected dose pergram of tissue basis.

General tissue distribution (TD) analysis: Biodistribution studies wereperformed in female mice according to the standard procedure developedby the inventors.²⁷ Radioiodinated NM404 (5 μCi in 100 μl) wasadministered via tail vein injection. At the predetermined time pointsanimals (3/time point) were euthanized by exsanguination while underpentobarbital anesthesia. A total of 16 tissues including blood, plasma,adrenal glands, bladder, bone marrow, fat, heart, kidney, liver, lung,muscle, spleen, ovaries, skin, thyroid, and tumor were excised, rinsed,and dissected free of extraneous tissue. Large organs were minced andduplicate tissue samples will be weighed and placed in plastic tubes forisotope counting. Injection site and residual carcass radioactivity werealso determined in a well counter. These standard procedures have beenutilized for many years in the inventor's laboratory under appropriateanimal care and radiation safety approval. Tissue distribution tableswere generated by a computer program which produces decay-correctedtissue radioactivity concentration data on a percent injected dose/g, %kg dose, and percent injected dose/organ +SEM basis. At each time point,tumor to tissue ratios were calculated based on a percent injected doseper gram of tissue basis. A control TD study (3 mice/time point, 15total mice) were performed on tumor bearing mice at 4, 7, 14, 21, and 28days most NM404 injection in order to establish comparative TD tablesfor all of the therapeutic regimens.

General imaging protocols: Animals received ¹²⁵I-NM404 (10 μCi) via tailvein injection and at predetermined timepoints thereafter wereanesthetized (sodium pentobarbital anesthesia, 0.06 mg/g bw) andunderwent radionuclide scanning using a Bioscan AR2000 radio-TLC scannermodified for mouse imaging (1 mm high resolution collimator/1 minacquisition time per lane/1 mm lane increments). Data were quantitatedand presented using Winscan 2D software from Bioscan. Once excised,control and treated tumors were also scanned ex vivo on the Bioscan unitin order to allow for more accurate ROI analysis by eliminating wholebody radionuclide attenuation. Animals (sodium pentobarbital anesthesia,0.06 mg/g bw) underwent microCT scanning (Imtek MicroCAT I, 390 stepacquisition/43Kvp/410 μA) using medium resolution acquisitionparameters. Data sets were reconstructed 3-dimensionally and arevisualized with AMIRA 3D-visualization software. The software allows forROI density analysis and convenient on-screen measuring.

B. Example II Preclinical Studies with First Generation PLE Analogs

Phospholipid ethers can easily be labeled with iodine radioisotopesusing an isotope exchange method developed by the inventors.¹⁹ Theiodophenyl phospholipid ether analogs are specifically designed so thatthe radioiodine affixed to each molecule is stable to facile in vivodeiodination. Over 20 radiolabeled PLE compounds were synthesized andtested in vitro and in vivo.²⁰⁻²² Two of these, namely NM294 and NM324[12-(3-iodophenyl)-dodecyl-phosphocholine], initially showed the mostpromise in animal tumor localization studies. These prototype compounds,labeled with iodine-125, selectively localized in tumors over time inthe following animal tumor models; 1) Sprague-Dawley rat bearing Walker256 carcinosarcoma; 2) Lewis rat bearing mammary tumor; 3) Copenhagenrat bearing Dunning R3327 prostate tumors; 4) Rabbits bearing Vx2tumors; and 5) athymic mice bearing human breast (HT39), small cell lung(NCl-69), colorectal (LS174T), ovarian (HTB77IP3), and melanoma tumors.Optimal tumor localization of these agents takes from one to severaldays.

Mechanistic Studies with PLE Analogs: NM324 and NM404 are similar instructure to miltefosine (hexadecylphosphocholine), an antitumor etherlipid studied most extensively in Europe. The antitumor properties ofmiltefosine and several other antitumor phospholipid ether analogs havebeen demonstrated in a wide range of tumor cell lines includingprostate-, bladder-, and terato-carcinomas, murine and human leukemias,as well as lung, colon, ovarian, brain and breast cancers.²³ In contrastto many anticancer drugs, these phospholipid ether analogs do not binddirectly to DNA and are not mutagenic. Although the preciseantiproliferative mechanism of action has not been determined, theyapparently act at several tumor cell sites. These compounds have beenassociated with a variety of cellular effects including transport,promotion of cytokine formation, apoptosis induction, and interferencewith a variety of key lipid metabolism and cell signaling enzymes mostof which are located in the cellular membrane. Although a debate existsregarding the mode of uptake into cells, the majority of reports nowsupport the idea that these ether lipids are directly absorbed into cellmembranes where they accumulate. A widespread belief is that theseagents act by perturbing membrane phospholipid metabolism; however,cellular distribution studies with these agents have been limited byspontaneous cellular compartmental redistribution during homogenizationand subcellular fractionation procedures. In contrast to the tracerimaging doses (several pg) the inventors have employed, antitumoreffects are seen only at doses generally exceeding 300-1000 mg perday.²³

Formal metabolism studies were conducted on several PLE analogsincluding NM324, the predecessor of NM404. In these studies, each agentwas examined to determine their ability to serve as substrates forenzymes associated with PLE metabolism. As shown in FIG. 24, three majorenzymatic pathways are involved in the metabolism of PLE. O-Alkylglycerol monooxygenase (AGMO) is responsible for cleavage of the alkylether linkage at C-1 to form either the long chain fatty alcohol orsubsequently, the corresponding fatty acid. Phospholipases C (PL_(C))and D (PL_(D)), on the other hand, give rise to the glycerol orphosphatidic acid products, respectively. Using a microsomal AGMO enzymepreparation, NM324 was not a substrate for this enzyme when compared to[³H]-lyso-PAF (platelet activating factor), which was extensivelymetabolized. In a similar fashion, NM324 was analyzed as a substrate forPL_(C) isolated from Bacillus cereus and was not hydrolyzed relative to1-palmitoyl-2-[3H]-palmitoyl-L-3-phosphatidylcholine (DPPC), whichunderwent significant hydrolysis.

Finally, several PLE analogs were subjected to a PLD assay. The PLD,which was isolated from cabbage, is similar to mammalian PL_(D) in thatthe cabbage form affords phosphatidylethanol-type products in additionto phosphatidic acid when the enzymatic reaction is performed in thepresence of ethanol. Several of the PLE analogs subjected to these assayconditions did give rise to the phosphatidylethanol adduct, indicatingpossible interaction with PL_(D).

Several NM404 precursors were also subjected to in vitro metabolismstudies in various cell lines including Walker tumor cells, rat muscle(H9c2), and rat hepatocytes. In these studies, the extent of metabolismwas determined on the basis of radiolabeled products formed afterincubation for various time periods and the results normalized to cellnumber or the amount of cellular protein. Subsequent lipid extraction ofthe incubation medium and cell suspension demonstrated little generationof PLE metabolites in the Walker tumor cells whereas a significantproduction of metabolites was seen in both the muscle cells andhepatocytes over the 48 h time period studied. These results correlatenicely with in vivo biodistribution studies completed on all analogs.Although several studies have been completed, the role of metabolictrapping in the uptake and retention of radiolabeled PLE analogs intumor cells is not well defined and currently remains an active area ofexamination.

Clinical Evaluation of NM324: Of several promising first generation PLEanalogs, NM324 was more readily synthesized and was thus selected as thelead compound for initial clinical studies. Although images obtained in5 human lung cancer patients detected tumors, images were complicated byhigh liver radioactivity (FIG. 2).

Second Generation PLE Analogs: In order to decrease liver uptake andprolong the plasma phase, 9 structural analogs of NM324 were synthesizedand radiolabeled with ¹²⁵I for initial image analysis in Copenhagen ratsbearing Dunning R3327 prostate tumors. Based upon this initial screen,NM347, NM404 [18-(4-iodophenyl)-octadecylphosphocholine] and NM412 (FIG.3) were selected to undergo further imaging and biodistribution analysisin animal-tumor models.

More recent imaging studies with NM404 and NM412 in animal models showedthat both were superior to NM324 in visualizing a variety of tumors.Significantly, lymph node metastases were clearly delineated in ametastatic prostate tumor model following intravenous administration ofeither NM404 or NM412. Most importantly, the tracer was not retained byuninvolved lymph nodes.²⁴ (FIG. 4A). Although conducted in a prostatemodel, this finding is particularly relevant to breast cancer whereinlymph node involvement is such an important prognostic indicator. Apreliminary pilot study conducted in SCID mice bearing human A549 NSCLCtumors were encouraging and demonstrated that NM404 overcomes theproblem of high first pass clearance of NM324 by the liver. NM404 showsexcellent tumor visualization, especially striking in the delayedimages, with minimal liver and kidney uptake in comparison with NM324(FIG. 4). Tissue biodistribution studies further confirmed the highlevels of radioactivity residing in the tumors. Although imaging resultswere similar with NM404 and NM412, dosimetry data obtained in ratsrevealed lower kidney doses were found with NM404 relative to NM412, andthus NM404 was selected for further studies. Comparative biodistributiondata for NM324 and NM404 in SCID mice with prostate and A549 lung cancertumor models have revealed high tumor to normal tissue ratios and tumoruptake exceeding 25% of the injected dose with NM404.

Animal imaging studies performed in mouse models aimed at determiningthe uptake characteristics in a wide variety of tumor models aresummarized in Table 1. Preliminary results in B6 Apc^(Min)/+ miceindicate that NM404 is not taken up by adenomatous polyps but is takenup and retained by mammary adenocarcinomas in this model, thusindicating a possible specificity for malignant tumor cells. Thesestudies are aimed at determining the potential of NM404 to noninvasivelycharacterize tumors. NM404 has displayed significant tumor uptake andretention in every adenocarcinoma model studied.

TABLE 1 Summary of tumor models examined with NM404 Tumor Model SpeciesCategory Uptake Human Tumor Xenografts Prostate PC-3 SCID MouseAdenocarcinoma Yes Lung A-549 (NSCLC) SCID Mouse Adenocarcinoma Yes LungNCI H-69 (Oat Nude Mouse Adenocarcinoma Yes Adrenal H-295 SCID MouseAdenocarcinoma Yes Adrenal RL-251 SCID Mouse Adenocarcinoma Yes MelanomaA-375 Nude Mouse Adenocarcinoma Yes Colon LS-18O Nude MouseAdenocarcinoma Yes Ovarian HTB-77 Nude Mouse Adenocarcinoma Yes AnimalTumor Xenografts Mammary MCF-7 Rat Adenocarcinoma Yes Prostate MatLyLuRat Adenocarcinoma Yes Walker-256 Rat Carcinosarcoma Yes Recent RodentModels TRAMP prostate Spontaneous mouse Adenocarcinoma Yes Liver CT-26Mouse xenograft Colorectal adenocarcinoma Yes Subcutaneous CT-26 Mousexenograft Colorectal adenocarcinoma Yes Min Mouse Intestinal EndogenousMouse Adenocarcinoma Yes Melanoma Mouse xenograft Adenocarcinoma YesSCC1 and 6 Nude mouse Squamous cell carcinoma Yes Mammary SCC and ACApc^(Min/+)mouse SCC and Adenocarcinoma Yes Hepatocellular CarcinomaSpontaneous mouse Adenocarcinoma Yes Retinoblastoma Spontaneous mouseBlastoma Yes Cervical Adenocarcinoma Spontaneous mouse AdenocarcinomaYes Pancreatic c-myc and kras Spontaneous mouse Adenocarcinoma YesGlioma L9 Rat Xenograft Glioma Yes Intestinal polyp Apc^(Min/+)mouseAdenoma No¹ Mammary Hyperplasia Apc^(Min/+)mouse Alveolar HyperplasiaNo¹ ²Tumor uptake was <<1% injected dose/gram

Relevance of CT26 Murine Tumor Model: Inventors explored NM-404 as apredictor of tumor response in a murine (BALB/c mice) model withsubcutaneous CT26 cell inoculation into the flanks of the mice. The CT26cell line is a poorly differentiated murine adenocarcinoma that wasinduced by rectal injection of N-nitroso-N-methylurethane in BALB/cmice. The cell line is simple to grow in vitro and results in apredictable growth pattern when injected in the vasculature (tail veininjection, metastatic model), or into the skin (FIG. 5) orliver.^(25,26) Because the cell line is derived from a colorectalcancer, this murine model is highly clinically relevant for thesestudies.

Preliminary Imaging Results with NM404 in CT26 Tumors: In a preliminaryexperiment to show that NM404 localizes in subcutaneous CT26 xenografts,two animals were injected (IV tail vein) with ¹²⁵I-NM404 (10 μCi) andsubsequently imaged on a modified Bioscan AR2000 radio TLC scanner(equipped with high resolution 1 mm collimator and 2-D acquisition andanalysis software) at 1, 4, and 7 days post injection. On day 7, theanimal was euthanized and the tumor removed, photographed, and scannedex vivo on the Bioscan (FIG. 6). Ex vivo scanning is standard protocolin the inventor's lab due to the severe tissue attenuation effectsassociated with iodine-125. Each animal also underwent microCT scanning(FIG. 7) on day 7 prior to euthanasia and dissection of the tumor. Focalhot spots correlated visually with all tumors on ex vivo Bioscan images(FIG. 6). Although lymph nodes are visible, no radioactivity wasassociated with them indicating a lack of tumor cell infiltration. Themain tumor in FIGS. 6 and 7 was histologically categorized as anadenocarcinoma. The inventors have scanned a wide variety ofsubcutaneous tumors via microCT and all are very easily detectable downto less than 300 microns in diameter.

Initial RF ablation of a subcutaneous mouse CT26 tumor was successfuland resulted in severe cellular damage (FIG. 8) as indicated by the lossof cellular membranes in the treated H&E-stained section.

C. Example III Non-Small Cell Lung Cancer

Imaging and biodistribution studies were performed in SCID (severecombined immune deficiency mutation) mice bearing the human NSCLCadenocarcinoma A549 cell line (adenocarcinoma has become the mostfrequent human lung cancer histologic type). Preliminary pilot resultsin five animals were encouraging and demonstrated that the new agentNM404 overcomes a limitation of the NM-324 compound. While there isreasonably good tumor uptake with NM324, imaging is compromised by ahigh first pass clearance by the liver. However, NM404 shows excellenttumor visualization, especially striking in the delayed images, withminimal liver and kidney uptake. Moreover, tissue biodistributionstudies further confirmed the high levels of radioactivity residing inthe tumors. A comparison of NM324 and NM404 images in a SCID mouse-humanNSCLC model are shown in FIG. 4. Note the relative lack of liver, kidneyand gut activity with NM404, coupled with excellent tumor visualization.Although imaging results were similar with NM404 and NM412, recentdosimetry data obtained in rats revealed lower kidney doses were foundwith NM404 relative to NM412, and thus NM404 has been selected forfurther studies.

Extensive biodistribution data for the prototype agent ¹²⁵I-NM324 inseveral tumor models have previously been compiled. Counsell R E,Schwendner S W, Meyer K L, Haradahira T, Gross M D. Tumor visualizationwith a radioiodinated phospholipid ether. J Nucl Med 31(3):332-336,1990; Plotzke K P, Fisher S J, Wahl R L, Olken N M, Skinner S, Gross MD,Counsell R E. Selective localization of a radioiodinated phospholipidether analog in human tumor xenografts. J Nucl Med 34(5):787-792, 1993;Rampy M A, Brown R S, Pinchuk A N, Weichert J P, Skinner R W, Fisher SJ, Wahl R L, Gross M D, Etheir S P, Counsell R E. Biological dispositionand imaging of a radioiodinated alkylphosphocholine in two rodent modelsof breast cancer. J Nucl Med 37(9):1540-1545, 1996. Tumor-to-bloodratios exceeding 8:1 were seen at delayed times post-injection. Forexample, in a rat mammary tumor model, tumor-to-normal tissue ratiosreached a maximum at 96 hours with a tumor-to-blood ratio of 8.6 andtumor-to-muscle ratio of 20:1. Rampy M A, Brown R S, Pinchuk A N,Weichert J P, Skinner R W, Fisher S J, Wahl R L, Gross M D, Etheir S P,Counsell R E. Biological disposition and imaging of a radioiodinatedalkylphosphocholine in two rodent models of breast cancer. J Nucl Med37(9):1540-1545, 1996. Moreover, the biodistribution of PLE-associatedradioactivity is heterogeneous in tumor, as demonstrated bymicroautoradiography studies showing that the PLE radioactivity residesexclusively in viable tumor cells located toward the outer regionsrather than the central necrotic regions. Rampy M A, Brown R S, PinchukA N, Weichert J P, Skinner R W, Fisher S J, Wahl R L, Gross M D, EtheirS P, Counsell RE. Biological disposition and imaging of a radioiodinatedalkylphosphocholine in two rodent models of breast cancer. J Nucl Med37(9):1540-1545, 1996. Comparative biodistribution data for NM324 andNM404 in SCID mice thus far have only been performed in prostate andA549 lung cancer tumor models. These studies have revealed high tumor tonormal tissue ratios and tumor uptake exceeding 25% of the injected dosewith NM404, thus supporting our desire to study the biodistribution ofPLE analogs in more spontaneous tumor models and humans.

One additional study addressing the relative sensitivity of NM404 toNM324 was performed in a SCID mouse A549 lung cancer model. The lungs ofeach animal were excised 10 days after administration of equal doses ofeach agent and imaged ex vivo for one hour in order to enhanceresolution. The low resolution and highly amplified images shown in FIG.23 revealed the presence of a focal radioactivity in the lungs of bothanimals imaged with NM404 and little or no uptake in the NM324 pair.Subsequent pathologic analysis confirmed the presence of small A549micro-metastases (less than 1 mm in diameter) in all 4 animals. Thecount rate in the NM404 mice was greater than 2.5 times that in thecorresponding NM324 mice, again indicating a superiority of NM404 overNM324.

It is likely that because the tumor-targeting strategy appears toinvolve selective tumor retention over time, relatively short-livednuclides such as ¹⁸F or even ^(99m)Tc are not practical for labeling atthe current time. However, as with the early use of monoclonalantibodies, which were labeled exclusively with radioisotopes of iodine,it may be possible in the future to label PLE analogs with alternativelabels, such as iodine-124, wherein the physical half-life matches wellwith PLE tumor uptake and retention kinetics. In fact, the utility of¹²⁴I-labeled NM404 as a tumor selective PET agent is the subject of apilot project for our microPET acquisition. The aim of that project isto evaluate the feasibility of labeling NM404 with iodine-124, arelatively new positron isotope with a 4-day physical half-life, and toevaluate its promise for PET imaging of tumors in small animal models.In addition to capitalizing on the resolution enhancement and3-dimensional capabilities PET imaging affords relative to traditionalgamma camera imaging, this approach would compliment the use offluorine-18 FDG in that its uptake into tumor cells occurs via adifferent biochemical mechanism than glucose utilization.

As has been discussed above, the utility of currently available tracers(e.g. ⁶⁷Ga and ¹⁸F-FDG) is limited by lack of specificity to distinguishneoplasm from inflammation. However, preliminary studies with PLE agentshas offered promise in overcoming this clinically significant limitationwherein carrageenan-induced granulomas in rats failed to visualize abovebackground activity and showed no tissue retention. Counsell R E,Schwendner S W, Meyer K L, Haradahira T, Gross M D. Tumor visualizationwith a radioiodinated phospholipid ether. J Nucl Med 31(3):332-336,1990. Gallium citrate, however, utilized as a control in that study, didconcentrate significantly in the granuloma. Such findings furtherjustify extending the inventors” studies with PLE analog agents aspotentially useful tumor-selective imaging agents.

Human Studies: Based upon the very promising pharmacokinetic and imagingdata in animals, the inventors were encouraged to move studies ofradiolabeled phospholipid ethers into the clinical arena. UnlabeledNM404 was initially assessed for its acute toxic effects on rats andrabbits in studies conducted at the Toxicology Research Center, StateUniversity of New (SUNY) at Buffalo. No toxic effects were seen at adose level of 3.2 mg/kg (>150 times the highest anticipated human dose)in these acute dose toxicology studies. Moreover, no platelet activatingproperties were demonstrated at this high dose level.

Unlabeled NM324 was administered to five normal, disease-free, humans inorder to gain approval of the radiolabeled agent for humanadministration by the Radioactive Drug Research Committee (RDRC). Thesesubjects had no evidence of toxicity, as manifested by symptoms,clinical examination, vital signs and sequential blood chemistries.

As a pilot feasibility project, 4 lung cancer patients were studiedunder RDRC approval with ¹³¹I-labeled NM324 at the Ann Arbor, Michigan VA hospital. Lung tumors were clearly visualized in all three of thepatients with lung cancer (two with NSCLC and one with small cell lungcancer), described in detail below. Degree of tumor uptake, at varioustime points, varied from 1+ (barely perceptible above background) to 3+(intense uptake, much greater than normal structures). Note that thepatients selected for these initial studies were those with known,relatively large cancers. It was not intended at this stage to studypatients in whom problems of tumor staging existed.

Case Histories:

Patient 01 was a 55 year old woman with a right middle lobe lung masseroding into the right ribs, histologically a mucin-producingadenocarcinoma of probable lung origin. Initial ¹³¹I-NM324 scintigraphicimages at 6 hours showed a focus of uptake in the right lateralmid-lung. For reasons unrelated to the scintigraphic study, the patientwas unable to return to the hospital beyond 6 hours for further imagingsession.

Patient 02 was a 62 year old man with a large (9×7×7.5 cm), lobulatedmediastinal mass extending from the aortopulmonary window and lefthilum. Tissue type was a small cell undifferentiated (oat cell)carcinoma. ¹³¹I-NM324 scintigraphic images revealed a focus of uptake inthe left upper lung, which increased in intensity over time relative tothe normal background activity.

Patient 03, a 74 year old man with a right upper lobe NSCLC(adenocarcinoma) treated 5 months previously with radiation therapy.Disease recurred in the left lingula (2.5×2×3 cm mass), lower thoracicspine (approx. T8) and right lobe of the liver. ¹³¹I-NM324 scintigraphyshowed well defined uptake in the lung mass and thoracic spine lesion,which demonstrated increasing target to background ratios over time(FIG. 2). Uptake in the liver metastasis could not be resolved above thenormal liver background.

These studies provided an early glimpse of the clinical promise ofradiolabeled PLE analogs. Although ¹³¹I is a suboptimal agent forimaging purposes, uptake in all three lung tumors was clearly depicted.As expected, based upon prior animal biodistribution experiments,activity in the tumors increased over time, as clearly demonstrated inpatients 02 and 03. In patient 03 tumor-to-normal tissue ratiosincreased from 2.74 at 2 days to 4.23 at 7 days. Patient 01 did notreturn for later imaging sessions beyond 6 hours. The increasingtarget-to-background ratios constitute strong evidence that themechanism for tumor visualization is not one based merely upon abnormalblood flow or tumor hypervascularity. Indeed, animal studies using^(99m)Tc human serum albumin confirmed this.¹

Clinical Trial Evaluating Patients With Non-Small Cell Lung Carcinoma(NSCLC) using NM404

Although NM404 has displayed selective and prolonged tumor retention in25/25 xenograft and spontaneous rodent models, a physician sponsored INDrecently initiated clinical evaluation of the agent in Stage 4 humannon-small cell lung cancer patients in order to determine whether or notit would exhibit similar tumor uptake and retention properties inhumans. To date, two patients with advanced NSCLC were imaged after aninjection of <1 mCi of ¹³¹I-NM404. Blood and urine samples werecollected at predetermined times, and gamma imaging performed at severaltime points following administration. In both patients, significanttumor uptake and retention of NM404 was demonstrated in the primary lungtumor, as seen in FIGS. 29 and 30. Relative to the high liver uptakevalues seen previously with its first generation predecessor, NM324,liver and abdominal activity are much lower with NM404, suggesting thefeasibility of evaluating this agent in other abdominal cancersincluding pancreatic, colon, and prostate.

Materials and Methods: Following intravenous injection of iodine-131labeled NM404 (1 mCi/20 μg), patients with advanced NSCLC where scannedat 3, 6, 24, 48, 96 h and at 7 and 11 days on a GE Maxxus dual HeadSPECT scanner. Blood and urine samples were collected forpharmacokinetic analysis as well as clinical hematologic, renal, andhepatic bioanalysis.

Results: Initial qualitative imaging results indicate that iodine-131labeled NM404 clearly localizes in bilateral pulmonary masses as earlyas 24 h after injection and is selectively retained in these tumors inexcess of 11 days. Moreover, background radioactivity in the liver andlower abdominal region including urinary bladder, kidneys, andintestines was significantly less than was observed previously with itspredecessor, NM324. No adverse reactions were observed in any of thepatients.

Conclusions: These preliminary findings suggest that NM404 exhibitssimilar tumor uptake and retention properties in human NSCLC as was seenpreviously in rodent models.

Although based on only two patients at this point, it appears that NM404does indeed localize in and undergo selective and prolonged tumorretention in human non-small cell lung cancer.

Patient 1: 55 year old male with bilateral 3 cm left lobe andinfiltrative right lobe NSCLC and a brain metastasis and a small rightadrenal mass. He has participated in numerous standard and experimentaltreatment regimens. Images are included in FIG. 29.

Patient 2: 70 year old male recently diagnosed with 6 cm upper lobe nonsmall cell mass, a 5 mm liver mass, an ilial bone met and a very smallbrain metastasis. He had recently completed low dose carboplatin/taxolchemotherapy and palliative radiotherapy to the ilial and brainmetastases the week prior to initiating the NM404 trial. Images areshown in FIG. 30.

D. Example IV Mouse Pancreatic Adenocarcinoma Models

Inventors also studied tumor avidity of NM404, a second-generation PLEanalog, in the c-myc mouse pancreatic adenocarcinoma model which isknown to produce invasive tumors with mixed acinar/ductal phenotype.

Materials and Methods: Two murine strains that are endogenous for eitherc-myc, or k-ras, well-known oncogenes, have been developed at theUniversity of Wisconsin.Sandgren E P, Quaife C J, et al., Proc Natl AcadSci USA. 1991; 88:93-97; Grippo P J. Nowlin P S. Et al., CancerResearch. 63(9):2016-9, 2003.

Expression of c-myc is targeted to pancreatic acinar cells because it islinked to an elastase promoter, which is only expressed in the pancreas.These ela-1-myc endogenous mice develop acinar and ductal neoplasia,which results in death between 2 and 7 months of age. By one month ofage, the pancreas appears thickened and firm. Thus mice between the agesof 1-3 months serve as excellent models for the study of pancreaticcancer. Most human pancreatic neoplasms have a ductal morphology and Dr.Sandgren's transgene targeting strategies are aimed at developing tumorsthat are specific for pancreatic ductal epithelium.

The c-myc model produces tumors that are invasive adenocarcinomas, withmixed acinar/ductal phenotype. The biology of the k-ras model ismarkedly different. The k-ras tumors have been classified as “carcinomain situ”, meaning that they have features of neoplasia, but they do notinvade and generally stay small (<2 mm). Their cellular appearance isfar more like the early human tumors so from a histological perspectivethey are a more relevant model of human disease. Further, they resemblethe very early stages of the human disease. The ability to detect the“early” development of the k-ras tumors versus the large and moreadvanced tumors in the c-myc mice would be an exceptionally importantstep toward identifying early (perhaps curable) lesions in humans. Thefact that k-ras mutations are the cause of over 90% of human pancreaticadenocarcinomas lends further support towards the validity of this modelfor the evaluation of new tumor imaging agents.

Imaging Studies: In order to determine if NM404 localizes in mousepancreatic tumors, six c-myc endogenous mice were scanned on a BioscanAR-2000 radioTLC scanner (modified in the inventors lab for mouseimaging) from 2-21 days after tail vein injection of ¹²⁵I-NM404 (15μCi/20 g bw). On the last day, mice also underwent microCT scanning (42kvp, 410 μA, 390 steps, MicroCAT-I, ImTek, Inc., Knoxville, Tenn.).Following in vivo imaging of anesthetized mice, the pancreatic tumorswere excised and scanned ex vivo on the same scanner (equipped with highresolution 1 mm collimator and 2-D acquisition and analysis software) inorder to avoid tissue attenuation associated with the low energy ofiodine-125 (FIG. 9-10) At sacrifice, tissues were excised, weighed, andradioactivity quantitated in a gamma counter.

Results and Discussion: Initial imaging results with NM404 in the c-mycmodel indicated striking uptake and prolonged retention (>21 days) inall adenocarcinomas ranging from 5-12 mm in diameter. As has beenobserved in previous cell culture and in vivo animal model studies,NM404 is apparently metabolized and eliminated from normal cells butbecomes metabolically trapped in tumor cell membranes. Previousautoradiography experiments in other tumor models have suggested thatonly viable tumor cells, and not normal tissue or necrotic tissues, arecapable of accumulating NM404. The inventors were also able to detectpancreatic tumors in live mice with microCT despite the ubiquitousnature of the pancreas in mice (FIG. 11) Although the number ofpancreatic tumor-bearing animals is small (n=6), preliminary NM404 tumorto background data appears promising.

Conclusions: NM404 displayed selective and prolonged retention inspontaneous pancreatic adenocarcinomas examined in this study, thusfurther extending the tumor selectivity of this agent.

E. Example V Rat Glioma Model

Materials and Methods: All animals were housed and handled in accordancewith the University of Wisconsin Research Animal Resources Centerguidelines. Rat C6 glioma cells were propagated in DMEM medium (LifeTechnologies, Gaithersburg, Md.) supplemented with 10% heat-inactivatedFBS (BioWhittaker, Walkersville, Md.), 100 U/ml penicillin G, 100 mg/mlstreptomycin, and 0.01 M HEPES (Life Technologies, Gaithersburg, Md.).Intracranial tumor implantation was performed as described previously(ref). Briefly, 1×10⁶ C6 cells were resuspended in 5 ml 1.2%methylcellulose and injected into the frontal lobes of anesthetizedfemale Wistar rats (Harlan, Indianapolis, Ind.). Sham-operated animalsreceived intracranial injections of an equal volume of methylcellulosewithout tumor cells.

Imaging Studies: Ten days after implantation, the presence ofintracranial tumors was confirmed with MRI. Briefly, anesthetized rats(6) received 2 ml of Gadodiamide (Gd, Omniscan 287 mg/ml, Nycomed,Princeton, N.J.) intraperitoneally and imaged 10 min later using a 1.5Tesla clinical MR system (GE Signa LX) and a GE phased array extremitycoil. The T1-weighted (TR=500 ms, TE=16.5 ms) multislice sequencescovering the entire brain of each rat were inspected to selecttumor-bearing rats with varying tumor sizes, and sham-operated rats forNM404 injections.

NM404 [18-(4-iodophenyl)-octadecylphosphocholine] (FIG. 3A, 100 mg) wasradioiodinated with ¹²⁵I via isotope exchange with Na¹²⁵I in a melt ofpivalic acid. Weichert, et al. Int J App. Rad Isotopes. 1986;37:907-913. Following HPLC purification NM404 was dissolved in anaqueous 2% Polysorbate 20 solution prior to tail vein injection (5-20μCi/200 g rat) into four tumor-bearing and three sham-operated rats. At1 (n=1), 2 (n=1), and 4 (n=2) days after NM404 injection, animals wereeuthanized (CO2) and brains were excised and imaged on a modifiedBioscan AR2000 radio-TLC scanner (1 mm increments at 2 minacquisition/lane and 1 mm high-resolution collimator). In addition,normal brain, blood, kidney, liver, spleen, thyroid, and tumor tissueswere weighed, and radioactivity counted in a gamma counter. The tissuedistribution of radioactivity was then correlated to brain histology.

Results and Discussion: Initial imaging results with NM404 indicatedstriking uptake and prolonged retention in all gliomas ranging from 3-5mm in diameter. Radioactivity in normal brain tissue was minimal in shamoperated control animals (FIG. 12), whereas NM404 concentrated intenselyin gliomas (FIG. 13). Tumor to brain ratios (% injected dose/g) inC6-bearing rats were 10.5, 12.2, and 6.7 at 24, 48, and 96 h,respectively. As has been observed in previous cell culture and in vivoanimal model studies, NM404 is apparently metabolized and eliminatedfrom normal cells but becomes metabolically trapped in tumor cellmembranes. Previous autoradiography experiments in other tumor modelshave suggested that only viable tumor cells, and not normal tissue ornecrotic tissues, are capable of accumulating NM404. Interestingly, evensmall tumors measuring a few mm in diameter, were also detected afterNM404 administration. These preliminary findings suggest that NM404 mayalso be useful for visualization of small invasive tumor foci.

Conclusion: As has been the case in all tumor models examinedpreviously, NM404 displayed selective and prolonged retention by ratC6-gliomas evaluated in this study.

F. Example VI Murine Liver Tumor

Preliminary results obtained in over 14 xenograft and spontaneous tumormodels have universally shown NM404 to undergo selective uptake andprolonged retention in tumors. Further, because NM404 affords lowerliver background levels than its predecessors, the inventors expandedevaluation into liver tumors in light of the fact that imaging patientswith HCC has been problematic. Many patients have underlying cirrhosisand therefore it is difficult to distinguish regenerating nodules fromHCC on cross sectional imaging. Moreover, preliminary studies evaluatingPET scanning with FDG have shown only 20-50% sensitivity in detectingthe disease. Verhoef C, Valkema R. et al., Liver (2002) 22:51-56.

Materials and Methods: Endogenous Mouse HCC Model. The development ofspontaneous hepatocellular cancer in endogenous mice over expressing theTGFα gene has been extensively evaluated and is an extremely promisinganimal model for study of this disease. Lee G H, Merlino G, Fausto N.Cancer Research (1992) 52:5162-5170. TGFα is a mitogen for epithelialcells and binds to the EGF receptor; unregulated expression of TGFαresults in tumor formation. In male CD1 mice expressing the transgeneTGFα under the control of the zinc-inducible metallothionine 1 (MT1)promoter, 75-80% develop HCC after 12 months of age. However, when thealkylating agent diethyinitrosamine (DEN), a chemical carcinogen, isused to induce tumor growth at 15 days of life, 90% of mice develop HCCby 6 months of age. On histologic examination, these tumors consist ofwell differentiated hepatocellular carcinomas of a solid pattern.Because the tumors arise spontaneously, the inventors utilize theseanimals as a suitable model for preclinical studies.

CT26 Colon Adenocarcinoma Xenograft Model: In addition to thespontaneous HCC model, NM404 was also evaluated in a xenograft colonadenocarcinoma tumor model whereby CT26 cells (5×10⁵ cells/50 μl) werepreviously injected directly into the liver parenchyma of female BALB/cmice for creation of focal liver tumors.

Imaging Studies: NM404 (FIG. 3A, 100 μg) was radioiodinated with ¹²⁵Ivia isotope exchange in a melt of pivalic acid. Weichert J P, et al.,Int J Applied Radiat Isot (1986) 37(8):907-913. Following HPLCpurification it was dissolved in an aqueous 2% Polysorbate 20 solutionprior to tail vein injection (15 μCi/20 g mouse) into 3 TGFα endogenousmice or alternatively into 3 CT26-tumor bearing mice. Mice wereanesthetized and scanned for up to 21 days post injection on a modifiedBioscan AR2000 radio-TLC scanner (1 mm increments at 2 minacquisition/lane and 1 mm high-resolution collimator) and also in anImTek microCT scanner (390 steps) for anatomic correlation. MicroCTimages were displayed using Amira software. At sacrifice, tumor-bearinglivers were initially excised and scanned ex vivo. Tumors were thenexcised, weighed, scanned ex vivo, and radioactivity quantitated. Lesionsamples were submitted for histologic classification.

Results and Discussions: Initial imaging results with NM404 (FIGS. 14,15) have shown striking uptake (>20% dose/g) and prolonged retention inboth spontaneous and implanted carcinomas in the liver. Tumor retentionof NM404 persisted in these animals for 21 days, the predetermined studyendpoint. Contrast-enhanced microCT images confirmed the presence andprecise location of all liver tumors (FIGS. 14, 16). Lipid extractionand subsequent HPLC analysis of tumor tissue indicated that theradioactivity was still associated with parent compound. As has beenobserved in previous cell culture and in vivo animal model studies,NM404 apparently is metabolized and eliminated from normal cells, butbecomes metabolically trapped in tumor cell membranes

Conclusions: As has been the case in all prior tumor models examined,NM404 displayed selective and prolonged retention by both spontaneousand xenograft murine liver tumor models evaluated in this study.

G. Example VII Apc^(Min)/+ Spontaneous Mammary Carcinoma Model

Materials and Methods: Apc^(Min)/+ Mouse Model: This model is comprisedof mice carrying the Min allele of Apc (Apc^(Min)/+ mice). This modeloffers specific advantages over xenograft models in that femaleApc^(Min)/+ mice are predisposed to develop mammary hyperplasias andcarcinomas and intestinal adenomas. On the C57BL/6J genetic background,about 5% of untreated females will develop a mammary tumor by 100 daysof age. Moser A R, Dove, et al. Proc Natl Acad Sci USA (1993)90:8977-81. The incidence and multiplicity of the mammary lesions can beincreased by a single dose of ethyinitrosourea (ENU), a direct actingalkylating agent. Treatment with ENU results in 90% of B6 Apc^(Min)/+females developing an average of 3 mammary squamous cell carcinomas(SCC), but few hyperplasic lesions within 60 days after treatment.

Apc^(Min)/+ mice carry a single base pair change in the Apc (adenomatouspolyposis coli) gene. The APC/Apc gene encodes a large protein withseveral potential functional domains. Groden, J., Thliveris, A.,Samowitz, W., Carlson, M., Gelbert, L., Albertsen, H., Joslyn, G.,Stevens, J., Spirio, L., Robertson, M. and et al. Identification andcharacterization of the familial adenomatous polyposis coli gene. Cell,(1991) 66, 589-600; Kinzler, K. W., Nilbert, M. C., Vogelstein, B.,Bryan, T. M., Levy, D. B., Smith, K. J., Preisinger, A. C., Hamilton, S.R., Hedge, P., Markham, A. and et al. Identification of a gene locatedat chromosome 5q21 that is mutated in colorectal cancers. Science,(1991) 257, 1366-70. The mouse and human APC proteins are 90% identicaland all potential functional domains are conserved. APC regulatesβ-catenin levels. β-catenin has multiple roles in the cell, includingstabilization of E-cadherin and regulation of transcription through theLEF and TCF family of transcription factors. Aberle, H., Schwartz, H.and Kemler, R. Cadherin-Catenin Complex—Protein Interactions and TheirImplications For Cadherin Function. Journal of Cellular Biochemistry,(1996) 67, 514-523; Huber, O., Korn, R., McLaughlin, J., Ohsugi, M.,Herrmann, B. G. and Kemler, R. Nuclear localization of beta-catenin byinteraction with transcription factor LEF-1. Mechanisms of Development,(1996) 59, 3-10; Behrens, J., Vonkries, J. P., Kuhl, M., Bruhn, L.,Wedlich, D., Grosschedl, R. and Birchmeier, W. Functional Interaction ofBeta-Catenin With the Transcription Factor Lef-1. Nature, (1996) 382,638-642. The regulation of β-catenin levels involves the interaction ofAPC, axin or conductin, and glycogen synthase kinase 3β (GSK3β) withβ-catenin. Behrens, J., Jerchow, B. A., Wurtele, M., Grimm, J., Asbrand,C., Wirtz, R., Kuhl, M., Wedlich, D. and Birchmeier, W. Functionalinteraction of an axin homolog, conductin, with beta-catenin, APC, andGSK3beta. Science, (1998) 280, 596-9; Ikeda, S., Kishida, S., Yamamoto,H., Murai, H., Koyama, S. and Kikuchi, A. Axin, a negative regulator ofthe Wnt signaling pathway, forms a complex with GSK-3beta andbeta-catenin and promotes GSK-3beta-dependent phosphorylation ofbeta-catenin. EMBO Journal, (1998) 77, 1371-84; Kishida, S., Yamamoto,H., Ikeda, S., Kishida, M., Sakamoto, I., Koyama, S. and Kikuchi, A.Axin, a negative regulator of the wnt signaling pathway, directlyinteracts with adenomatous polyposis coli and regulates thestabilization of beta-catenin. Journal of Biological Chemistry, (1998)273, 10823-6; Sakanaka, C., Weiss, J. B. and Williams, L. T. Bridging ofbeta-catenin and glycogen synthase kinase-3beta by axin and inhibitionof beta-catenin-mediated transcription. Proceedings of the NationalAcademy of Sciences of the United States of America, (1998) 95, 3020-3;Rubinfeld, B., Albert, I., Porfiri, E., Fiol, C., Munemitsu, S. andPolakis, P. Binding of GSK3beta to the APC-beta-catenin complex andregulation of complex assembly. Science, (1996) 272, 1023-6; Rubinfeld,B., Souza, B., Albert, I., Muller, O., Chamberlain, S. H., Masiarz, F.R., Munemitsu, S. and Polakis, P. Association of the APC gene productwith beta-catenin. Science, (1993) 262, 1731-4; Polakis, P. Theadenomatous polyposis coli (APC) tumor suppressor. Biochimica etBiophysica Acta, (1997) 7332, F127-47. This interaction results in thephosphorylation of β-catenin, which targets it for degradation by theubiquitin-proteasome pathway. Rubinfeld, B., Souza, B., Albert, I.,Muller, O., Chamberlain, S. H., Masiarz, F. R., Munemitsu, S. andPolakis, P. Association of the APC gene product with beta-catenin.Science, (1993) 262, 1731-4; Su, L. K., Vogelstein, B. and Kinzler, K.W. Association of the APC tumor suppressor protein with catenins.Science, (1993) 262, 1734-7; Polakis, P. Mutations in the APC gene andtheir implications for protein structure and function. Current Opinionin Genetics & Development, (1995) 5, 66-71; Aberle, H., Bauer, A.,Stappert, J., Kispert, A. and Kemler, R. beta-catenin is a target forthe ubiquitin-proteasome pathway. EMBO Journal, (1997) 76, 3797-804.Most germline and somatic mutations in APC result in proteins missingsome or all of the β-catenin binding sites.^(26,28,29) Polakis, P.Mutations in the APC gene and their implications for protein structureand function. Current Opinion in Genetics & Development, (1995) 5,66-71; Nagase, H. and Nakamura, YMutations of the APC (adenomatouspolyposis coli) gene. Human Mutation. (1993) 2, 425-34; Beroud, C. andSoussi, T. APC gene: database of germline and somatic mutations in humantumors and cell lines. Nucleic Acids Research, (1996) 24, 121-4.Tworegions of APC are required for this interaction; the truncated proteinencoded by the Min allele lacks both of these regions; Polakis, P.Mutations in the APC gene and their implications for protein structureand function. Current Opinion in Genetics & Development, (1995) 5,66-71; Su, L. K., Kinzler, K. W., Vogelstein, B., Preisinger, A. C.,Moser, A. R., Luongo, C., Gould, K. A. and Dove, W. F. Multipleintestinal neoplasia caused by a mutation in the murine homolog of theAPC gene. Science, (1992) 256, 668-70. APC also has a role in thetransport of β-catenin out of the nucleus. Thus, in the absence of APCfunction, β-catenin would accumulate in the cytoplasm and nucleus,possibly affected both transcription of target genes and cell-cellinteraction through E-cadherin. APC mutations are frequent in severaltumor types in humans including intestinal tumors and other epithelialtumors. Loss of heterozygosity at the APC locus or increased levels ofβ-catenin have been found in more than 25% of breast cancers. Furuuchi,K., Tada, M., Yamada, H., Kataoka, A., Furuuchi, N., Hamada, J.,Takahashi, M., Todo, S., and Moriuchi, T. Somatic mutations of the APCgene in primary breast cancers. Somatic mutations of the APC gene inprimary breast cancers, American Journal of Pathology. (2000) 156:1997-2005; Jonsson, M., Borg, A., Nilbert, M., and Andersson, T.Involvement of adenomatous polyposis coli (APC)/beta-catenin signalingin human breast cancer. Involvement of adenomatous polyposis coli(APC)/beta-catenin signaling in human breast cancer, European Journal ofCancer. (2000) 36: 242-248. Thus, the types of lesions that appear inthese mice will be molecularly and histologically similar to breastcancers in humans.

Genetic background can affect the incidence, latency, and type ofmammary lesions that develop. For example, FVBxB6 Apc^(Min)/+ femalemice develop an average of 0.2 mammary tumors per mouse, but 4hyperplasias per mouse within 120 days of treatment. BALB/xB6Apc^(Min)/+ develop an average of 1.8 mammary tumors and 0.6hyperplasias per mouse. Moser A R, Hegge L F, Cardiff R D. CancerResearch (2001) 61:3480-3485. FVBxB6 and BALBxB6 Apc^(Min)/+ micedevelop both mammary SCC and adenocarcinomas (AC).

The hyperplastic lesions in the FVBxB6 Apc^(Min)/+ mice can beclassified as either alveolar hyperplasias or squamous nodules. Moser,A. R., Hegge, L. F., and Cardiff, R. D. Genetic background affectssusceptibility to mammary tumors and hyperplasias in Apc ^(Min) /+ mice,Genetic background affects susceptibility to mammary tumors andhyperplasias in Apc^(Min)/+ mice. Cancer Research (2001) 61:3480-3485.Alveolar hyperplasias are precursors to the adenocarcinomas and thesquamous nodules are precursor lesions to the SCC. Thus, by manipulationof the genetic background, mice that develop multiple types ofhyperplasias and carcinomas may be generated, often within the sameanimal. The alveolar hyperplasias resemble atypical lobules (type A)commonly found in samples from human breasts. Cardiff, R. D. andWellings, S. R. The comparative pathology of human and mouse mammaryglands. The comparative pathology of human and mouse mammary glands,Journal of Mammary Gland Biology & Neoplasia. (1999) 4: 105-22. Theseatypical lobules are more common in cancerous breasts or in thecontralateral breast in women with breast cancer. While SCC is not afrequent type of breast tumor, the AC resembles a common type of humanbreast tumor. In addition, tumors with alterations in the APC pathwayare common in human breast cancers. Loss of heterozygosity at the APClocus or increased levels of β-catenin have been found in more than 25%of breast cancers. Furuuchi, K., Tada, M., Yamada, H., Kataoka, A.,Furuuchi, N., Hamada, J., Takahashi, M., Todo, S., and Moriuchi, T.Somatic mutations of the APC gene in primary breast cancers. Somaticmutations of the APC gene in primary breast cancers, American journal ofPathology. (2000) 156::1997-2005.35. Jonsson, M., Borg, A., Nilbert, M.,and Andersson, T. Involvement of adenomatous polyposis coli(APC)/beta-catenin signaling in human breast cancer. Involvement ofadenomatous polyposis coli (APC)/beta-catenin signaling in human breastcancer, Eur Journal of Cancer. (2000) 36: 242-248. Thus, the types oflesions that appear in these mice will be molecularly and histologicallysimilar to breast cancers in humans. One of the unique aspects andstrengths of this model is the ability to generate mice that developmultiple types of mammary hyperplasias and carcinomas, often within thesame animal. In this way we can test the uptake and retention of NM404in multiple types of hyperplasias and tumors within the same animal.

Polyoma virus infection of mice leads to the development of numeroustumor types including mammary tumors. Endogenous mice expressing thepolyoma middle T antigen (PyVT) under the control of the mouse mammarytumor virus LTR (MMTV) develop multifocal mammary dysplasias and tumorsrapidly. Amy Moser; Guy, C. T., Cardiff, R. D., and Muller, W. J.Induction of mammary tumors by expression of polyomavirus middle Toncogene: a endogenous mouse model for metastatic disease. Induction ofmammary tumors by expression of polyoma virus middle T oncogene: atransgenic mouse model for metastatic disease, Molecular & CellularBiology. (1992) 12: 954-61. Evidence for in situ carcinoma can be seenas early as three weeks of age, with 100% incidence of mammary tumors byas early as 5 weeks of age. The tumors are primarily classified as ACand/or adenoacanthomas. The mice develop multiple metastatic lesions inthe lung within 50 days of the appearance of the primary tumor Lifsted,T., Le Voyer, T., Williams, M., Muller, W., Klein-Szanto, A A., Buetow,K. H., and Hunter, K. W. Identification of inbred mouse strainsharboring genetic modifiers of mammary tumor age of onset and metastaticprogression. Identification of inbred mouse strains harboring geneticmodifiers of mammary tumor age of onset and metastatic progression, IntJ of Cancer. (1998) 77: 640-4. Thus, these mice provide a rapid modelfor metastatic mammary cancer. As with the Apc^(Min)/+ mice, geneticbackground affects the time course of tumor development and metastaticspread. Lifsted, T., Le Voyer, T., Williams, M., Muller, W.,Klein-Szanto, A A., Buetow, K. H., and Hunter, K. W. Identification ofinbred mouse strains harboring genetic modifiers of mammary tumor age ofonset and metastatic progression. Identification of inbred mouse strainsharboring genetic modifiers of mammary tumor age of onset and metastaticprogression, Int J of Cancer. (1998) 77: 640-4. Thus, the inventors usecrosses to generate mice with a slower course of tumor development. PyVTcan associate with members of the SRC kinase family,phosphatidylinositol-3″kinase, the SHC adapter protein and proteinphosphatase 2A. Dankort, D. L. and Muller, W. J. Transgenic models ofbreast cancer metastasis. Transgenic models of breast cancer metastasis,Cancer Treatment & Research. (1996) 83: 71-88. Activation of SRC familykinases is frequently observed in human breast tumors. AmyMoser;Muthuswamy, S. K. and Muller, W. J. Activation of the Src familyof tyrosine kinases in mammary tumorigenesis. Activation of the Srcfamily of tyrosine kinases in mammary tumorigenesis, Advancesin CancerResearch (1994) 64: 111-23.

Imaging Studies: NM404 (FIG. 3A, 100 μg) was radioiodinated with ¹²⁵Ivia isotope exchange in a melt of pivalic acid. Following HPLCpurification it was dissolved in an aqueous 2% tween-20 solution priorto tail vein injection (15 μCi/20 g mouse) into 6 female Apc^(Min)/+mice. Mice were anesthetized and scanned for up to 50 dayspost-injection on a modified Bioscan AR2000 radio-TLC scanner (1 mmincrements at 2 min acquisition/lane and 1 mm high-resolutioncollimator) and also in an ImTek microCT scanner (390 steps) foranatomic comparison. MicroCT images were displayed using Amira software.At sacrifice, mammary glands or excised tumors were imaged ex vivo,lesions were excised, weighed, and radioactivity quantitated. Lesionsamples were submitted for histologic classification. If necessary along-acting CT blood pool contrast agent (BP10), developed in theinventors' lab and suitable for long microCT acquisition times wasinjected intravenously prior to CT scanning in order to assist in bloodvessel visualization. (FIG. 19). Weichert J P, et al., Radiology (2000)216:865-871.

Results and Discussion: This model is unique in that hyperplasticmammary lesions, mammary carcinomas, and intestinal adenomas develop inthe same mouse. Initial imaging results with NM404 (FIGS. 17, 18) haveshown striking uptake (>20% dose/g) and prolonged retention in allspontaneous mammary carcinomas ranging from 2-15 mm in diameter.Although tumor localization appears rapid, background radioactivitypersists for several days in liver and gut during the body clearancephase. HPLC analysis of radioactive urine and feces indicated thepresence of metabolites and no parent NM404. Tumor retention of NM404persisted for 50 days, the predetermined study endpoint. NM404 did notlocalize, however, in intestinal adenomatous polyps found frequently inthese mice (FIG. 18). MicroCT images confirmed the presence and preciselocation of all mammary tumors (FIG. 19). Lipid extraction andsubsequent HPLC analysis of tumor tissue indicated that theradioactivity was still associated with parent compound. As has beenobserved in previous cell culture studies, NM404 apparently ismetabolized and eliminated from normal cells but becomes metabolicallytrapped in tumor cell membranes.

Conclusions: NM404 has displayed striking tumor avidity in animal andhuman xenograft tumor models examined to date. Moreover, while itdisplayed selective and prolonged retention by mammary tumors in thisspontaneous tumor model it did not localize in associated intestinaladenomatous polyps.

H. Example VIII Specificity for Hyperplasia versus Neoplasia in theApc^(Min)/+ Endogenous Mammary Adenocarcinoma Model

Materials and Methods: Apc^(Min)/+ Mouse Model: This model is comprisedof mice carrying the Min allele of Apc (Apc^(Min)/+ mice). This modeloffers specific advantages over xenograft models in that femaleApc^(Min)/+ mice are predisposed to develop mammary hyperplasias andcarcinomas and intestinal adenomas. On the C57BL/6J genetic background,about 5% of untreated females will develop a mammary tumor by 100 daysof age. Moser A R, Dove, et al. Proc Natl Acad Sci USA (1993)90:8977-81. The incidence and multiplicity of the mammary lesions can beincreased by a single dose of ethyinitrosourea (ENU), a direct actingalkylating agent. Treatment with ENU results in 90% of B6 Apc^(Min)/+females developing an average of 3 mammary squamous cell carcinomas(SCC), but few hyperplasic lesions within 60 days after treatment.

Genetic background can affect the incidence, latency, and type ofmammary lesions that develop. For example, FVBxB6 Apc^(Min)/+ femalemice develop an average of 0.2 mammary tumors per mouse, but 4hyperplasias per mouse within 120 days of treatment. BALB/xB6Apc^(Min)/+ develop an average of 1.8 mammary tumors and 0.6hyperplasias per mouse. Moser A R, Hegge L F, Cardiff R D. CancerResearch (2001) 61:3480-3485. FVBxB6 and BALBxB6 Apc^(Min)/+ micedevelop both mammary SCC and adenocarcinomas (AC).

Imaging Studies: NM404 (FIG. 3A, 100 μg) was radioiodinated with ¹²⁵Ivia isotope exchange in a melt of pivalic acid. Following HPLCpurification it was dissolved in an aqueous 2% tween-20 solution priorto tail vein injection (15 μCi/20g mouse) into 6 female Apc^(Min)/+mice. Mice were anesthetized and scanned for up to 30 days postinjection on a modified Bioscan AR2000 radio-TLC scanner (1 mmincrements at 2 min acquisition/lane and 1 mm high-resolutioncollimator) and also in an ImTek microCT scanner (390 steps) foranatomic comparison. MicroCT images were displayed using Amira software.At sacrifice, mammary glands or excised tumors were imaged ex vivo,lesions were excised, weighed, and radioactivity quantitated. Lesionsamples were submitted for histologic classification. If necessary along-acting CT blood pool contrast agent (BP20), developed in theinventors' lab and suitable for long microCT acquisition times wasinjected intravenously prior to CT scanning in order to assist in bloodvessel visualization (FIG. 22). Weichert J P, et al., Radiology (2000)216:865-871.

Results and Discussion: This model is unique in that hyperplasticmammary lesions, mammary carcinomas, and intestinal adenomas develop inthe same mouse. Initial imaging results with NM404 (FIGS. 20, 21) haveshown striking uptake (>20% dose/g) and prolonged retention in allspontaneous mammary carcinomas ranging from 2-15 mm in diameter.Although tumor localization appears rapid, background radioactivitypersists for several days in liver and gut during the body clearancephase. HPLC analysis of radioactive urine and feces indicated thepresence of metabolites and no parent NM404. Tumor retention of NM404persisted for >21 days, the predetermined study endpoint. NM404 did notlocalize, however, in either focal alveolar hyperplasias or inintestinal adenomatous polyps found frequently in these mice (FIG. 21).MicroCT images confirmed the presence and precise location of allmammary tumors (FIG. 22). NM404 apparently is metabolized and eliminatedfrom normal cells but becomes metabolically trapped in tumor cellmembranes.

Conclusions: NM404 has displayed striking tumor avidity in 20/20 animaland human xenograft tumor models examined to date. Moreover, while itdisplayed selective and prolonged retention by mammary adeno- andsquamous cell carcinomas in this spontaneous tumor model, it did notlocalize in associated focal alveolar hyperplasias or intestinaladenomatous polyps and thus appears to be selective for malignant tumorcells.

I. Example IX Mechanism of Selective Retention of NM404

Introduction: Certain phospholipid ether analogs, such as NM404, areselectively retained within many types of tumor cells for a prolongedtime. The inventors sought to evaluate the mechanism of selectiveretention of NM404 in tumor cells using both an enzymatic assay toevaluate the activity of phospholipase D (PLD) protein and quantitativePCR. The inventors hypothesized that reduced levels of PLD in tumorcells results in a decrease in the ability to metabolize and excreteNM404.

Methods: Single cell suspensions of murine tumor cell lines includinghepa-1 (hepatoma), CT26 (colorectal adenocarcinoma), and TS/A (breastadenocarcinoma) were analyzed with two assays: (1) Amplex® Red assay,using a commercially available kit (Molecular Probes) that evaluates PLDprotein activity using a fluorescence microplate reader, and (2)quantitative PCR to determine the level of PLD mRNA. Tumor cell lineswere compared to normal liver tissue, which exhibits higher levels ofuptake and elimination of NM404 and thus likely has lower PLD levelsthan other normal tissues. For the Amplex® Red assay, total protein wasextracted using a detergent solution (Triton-X-100) and quantity of PLDcompared to a standard positive control. For PCR, mRNA was purified andconverted to cDNA using reverse transcriptase (Promega). Conditions foramplification of cDNA for real-time PCR included: (94° C., 30 sec; 65°C., 30 sec; and 72° C., 30 sec) for 50 cycles (iCycler, iQmix,Bio-Rad).The primer for PLD1, (sense) 5′-TCTGGTTTCACCCCGTCAGM-3′,(antisense) 5′-TTGCTCATATCTGCGGCGAT-3′, was used. Product was comparedto a standard cDNA (GAPDH, Biosource) diluted from 1 μg to 10⁻⁷ μg. Allassays were performed in duplicate.

Results: PLD was quantitated as shown in the Table 3. Both PLD proteinactivity and mRNA levels were significantly lower than normal livertissue (p<0.05, T-test) in all cell lines.

Conclusion: Both reduced PLD protein activity and a decrease in PLD mRNAwere observed in murine tumor cell lines. Thus, the mechanism ofselective retention of NM404 may be due to a decrease in the breakdownof NM404 by PLD. Decreased PLD activity in tumor may serve as apotential molecular target for anti-tumor agents.

TABLE 3 PLD protein activity (mU/fluorescence/μg mRNA (μg × 10⁻⁵/0.01 μgof Cell/tissue protein/ml) total cDNA) Hepa-1 3.3 6.2 CT26 7.8 2.4 TS/A2.8 4.0 Normal liver 14.1 12.2

J. Example X Therapeutic attributes in Endogenous Murine Mammary TumorModel

Models for NM404 Therapy Study: Although long-term survival is notessential for imaging studies, it is advantageous for the proposedtherapy studies. The models used for imaging studies suffer fromconcomitant intestinal tumors which usually lead to the death of theanimal. In order to increase the number of tumors developing per mouseand decrease the number of intestinal tumors in hopes of increasing thelifespan of the tumor bearing mice, Dr. Moser has recently crossed maleB6 Min/+ mice with female C57BR/cdJ (BR) mice. The resulting BRB6 F1Min/+ female mice developed significantly more mammary tumors than didthe B6 Min/+ mice (P=0.016), an average of nearly 5. The number of micewith tumors and the time to first tumor were not different between thesetwo strains (P=1 and P=0.06, respectively) (FIG. 25). The increasedmammary tumor number of the BRB6 F1 mice may be due, in part, to thesignificantly longer survival times of the hybrid BRB6 F1 Min/+ micerelative to the B6 Min/+ mice (P=2×10⁻⁷).

B6 and BRB6 F1 Min/+ mice were very similar with respect to the mammarygland phenotype, but quite different in susceptibility to intestinaltumors. The B6 and BR strains can be considered sensitive backgroundsfor Min-induced mammary tumorigenesis as the mice developed a largenumber of tumors within a short time after ENU treatment. However, theBR strain carries dominant resistance alleles at modifier loci affectingintestinal tumor development, which may prove relevant to the proposedtherapy study. A comparison of these strains is presented in Table 2.

TABLE 2 Genetic background affects mammary and intestinal tumordevelopment in Min/+ mice. Average % with Average # of # with Average #of Average # of survival in # of mammary mammary mammary mammaryintestinal days after ENU Strain mice tumor ( ) tumors/mouse lesions (%)lesions/mouse tumors/mouse (range) B6 45 93 3.3 ± 2.0 17 (38)  0.6 ± 0.934 ± 10 64 (43–78) BR × B6 18 94 4.9 ± 2.6 7 (39) 0.5 ± 0.7 14 ± 4   91(58–118) FVB × B6 18 17 0.2 ± 0.5 18 (100) 4.1 ± 2.4   12 ± 6^(a)  127(93–178) ^(a)Information on 16 mice as the intestines of 2 mice werelost in processing. Mice were generated by crossing females of eachstrain with B6 Min/+ males. Female mice were treated with ENU whenbetween 30–45 days of age and sacrificed when moribund. Only the resultsfrom the Min/+ mice are shown. Mammary tumors are defined as thosetumors identified at necropsy, while mammary lesions are the small focallesions noted in the whole mounts of the 1^(st), 4^(th) and 5^(th)mammary glands. Intestinal tumors were counted in three 4 cmsectionsfrom the small intestine (duodenum, jejunum, and ileum), and the entirecolon. All Min/+ mice developed intestinal tumors. Values are the means± SD

Preliminary Imaging Results with NM404 in Min Mice: In a preliminaryexperiment to show that NM404 localizes in endogenous FVBxB6 Apc^(Min)/+mouse breast tumors, two animals were injected (IV tail vein) with¹²⁵I-NM404 (15 μCi) and imaged on a modified Bioscan AR2000 radioTLCscanner (equipped with high resolution 1 mm collimator and 2-Dacquisition and analysis software) at 1, 4, and 7 days post injection(FIG. 27A,B). Each animal underwent microCT scanning (FIG. 27) on day 10prior to euthanasia and dissection to remove the mammary glands andassociated tumors. Focal hot spots correlated visually with all tumorson ex vivo Bioscan images (FIG. 27C). Although lymph nodes are visible,no radioactivity was associated with them indicating a lack of tumorcell infiltration. The main tumor in FIG. 27C was histologicallycategorized as an adenocarcinoma. There were four mammary tumors in bothmice and all were easily detectable in ex vivo Bioscan images of theexcised mammary glands.

Radiotherapeutic Potential of NM404: During the course of recent mousetumor uptake and retention studies with “imaging” doses (15-20 μCi/20 gmouse) of ¹²⁵I-labeled NM404, several apparent therapeutic responseshave been observed (unpublished results). In an Apc^(Min)/+ mousemammary tumor model it has generally been noted that tumor growthremains static following a single intravenous injection of NM404. Someof these animals also lost all hair above larger mammary tumors ataround 8 days after injection. Moreover, these mice also get intestinaltumors and usually suffer from intestinal bleeding resulting in severeanemia, which renders their feet white. Dr. Moser noted that the feet ofthese mice had reverted to a pink color around 5 days after a singleinjection of NM404. Upon eventual dissection of these animals, it wasnoted that only a very few, if any, of the expected 20 or so intestinaltumors usually found at this age actually remained. The “white to pinkfeet” phenomenon was also observed in a separate, but more aggressive,mouse intestinal adenocarcinoma model, wherein dissection at 12 daysfollowing NM404 administration, again revealed that most, if not all, ofthe expected intestinal tumors were gone. In both intestinal models,animals that received NM404 easily outlived their untreated littermates. These coincidental findings were reconfirmed in two separateage-matched groups each involving more than 6 mice. These observationswith ¹²⁵I-NM404 indicate potential for radiotherapy applicationsparticularly if labeled with iodine-131. Quantitative tumor uptake andretention studies outlined in this proposed mammary tumor model willalso provide sufficient data to initiate a comprehensive dosimetryanalysis for this agent in order to estimate its true radiotherapeuticpotential.

Choice of Isotope: Due to its 60-day physical half-life and low energy28 KeV photon emission, iodine-125 is suitable for imaging experimentsin mice and rats. Iodine-125 also affords therapeutic characteristics aswell and is currently used in permanent prostate brachytherapy implants.In one imaging experiment, 2 nude mice were each inoculated withsubcutaneous squamous cell 1 and 6 tumor cell implants on opposingflanks. SCC1 and 6 cells were used because one is radiosensitiverelative to the other. After 14 days when the average tumor size (4total) was approaching 0.5 cm in diameter, one of the mice received 20μCi of ¹²⁵I-labeled NM404 and the other one receive unlabeled NM404 inan equal mass dose. The mouse that had received only the unlabeledcompound had to be euthanized 20 days after injection due to both tumorsreaching the termination size limit as defined in our animal useprotocol. Both tumors in the ¹²⁵I-NM404 mouse regressed dramatically andunexpectedly over the course of several weeks (FIG. 28). In fact, thetumors of this mouse never did reach terminal size and the mouse wasactually euthanized after 90 days in order to collect histologysections. At this time, the center of the tumor had become necroticwhile the peripheral rim appeared somewhat viable. Histologicexamination confirmed a necrotic center and viable rim. While bloodsupply factors can contribute to such observations it is also possiblethat the photon emission from ¹²⁵I resulted in poor electron equilibriumat the tumor periphery resulting in under-dosing of the “rind” of thetumor. This electron equilibrium issue is critical in radiationoncology. Photons travel a finite distance, determined by their energy,before interacting with tissue and exerting their biologic effect. Aphoton with too high an energy can result in under-dosing of the tumornodule periphery, as photons departing the nodule travel away (out ofthe tumor) before depositing their dose. This could be a problem with¹²⁵I the photons, however, the low energy insures very local deposition.Complex Monte Carlo calculations could refine such estimates, but thebest method for determining optimal isotope selection isexperimentation, as there are many factors at play which cannot bemodeled accurately (details of tissue distribution, multiple pass, etc).The one advantage of ¹²⁵I is that all the photons are of low energy,insuring very limited exposure of normal tissues surrounding the tumor.

Iodine-131 has been used with great efficacy in the treatment of thyroidcancer. Very safe doses of ¹³¹I can control subclinical deposits ofwell-differentiated thyroid cancer, which concentrates iodine veryavidly as does the normal thyroid. This active uptake process helpslimit the dose to normal tissues. Iodine-131 has both beta and severalgamma emissions, but the predominant tissue dose arises from the betaemissions. The inventors have selected ¹³¹I-labeled NM404 based upon theclinical success with thyroid cancer coupled with results obtained withBexxar (an iodine-131-labeled antibody-based agent) in low-gradelymphoma patients. The predominant beta emissions and mostly low energygamma emissions optimize dose homogeneity within the tumor noduleitself. Also, the shorter half-life (8-days) provides more clinicallyrelevant dose-intensity compared to the 60-day half-life of ¹²⁵I. Thesefactors will permit the inventors to make the best assessment of theanti-tumor efficacy of this agent. A potential disadvantage of ¹³¹I isthat there is a higher energy gamma emission as well which couldactually expose adjacent surrounding tissues to more radiation thanwould occur with ¹²⁵I. The tumors in the endogenous model proposedherein are peripherally located in the mammary glands and thus shouldnot represent an immediate threat to the overall well-being of theanimal. Since organ toxicity is also one of the study endpoints, thereaction of the surrounding tissue and key organ systems (marrow, liver,kidneys, bowel, brain, etc) is assessed. Tissue distribution data andactual dosimetry of radiolabeled NM404 will determine its optimaltherapeutic potential. It is possible that different isotopes willcomplement each other in the therapeutic setting.

It is understood that the examples and embodiments described herein arefor illustrative purposes only and that various modifications or changesin light thereof will be suggested to persons skilled in the art and areto be included within the spirit and purview of this application andscope of the appended claims. All publications, patents, and patentapplications cited herein are hereby incorporated by reference in theirentirety for all purposes.

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“DIAPEUTIC” is a trademark of Cellectar, LLC

What is claimed is:
 1. A method for the treatment of a cancer in asubject comprising administering to the subject an effective amount of amolecule comprising a phospholipid ether analog, wherein thephospholipid ether analog is 18-(p-iodophenyl)octadecyl phosphocholinewherein the iodo moiety of the 18-(p-iodophenyl)octadecyl phosphocholineis ¹²⁵I or ¹³¹I, and wherein said cancer is selected from the groupconsisting of lung cancer, squamous cell carcinoma, melanoma, colorectalcancer, ovarian cancer, prostate cancer, glioma, breast cancer,carcinosarcoma, and pancreatic cancer.
 2. The method of claim 1, whereinthe radioactive isotope of iodine is ¹³¹I.
 3. The method of claim 1,further comprising administering 5-20 μCi/200 g of body weight of thephospholipid ether analog to the subject.
 4. The method of claim 1,further comprising administering 15-20 μCi/200 g of body weight of thephospholipid ether analog to the subject.
 5. The method of claim 1,wherein the radioactive isotope of iodine is ¹²⁵I.